The following research questions address plant taxa that are globally or regionally rare. The New England Wild Flower Society has recently published comprehensive Conservation and Research Plans that review the conservation status of each taxon and that suggest specific actions to ensure their conservation within their New England range over the next twenty years. 

Abridged versions of Conservation and Research Plans are available for download at our web site, and provide an excellent general introduction to the ecology of the taxon and the known causes of its rarity. Most of these Plans pinpoint areas where we lack basic knowledge on the biology of the plant -- knowledge that is critical to understanding how best to conserve and protect it. Thus, the New England Wild Flower Society seeks to promote basic research studies that will elucidate the factors that influence plant fitness, interactions among populations, and population trends. These studies may yield some of the first data available on these plants, and will assist with conservation planning for these and many other rare plants. The questions that follow derive directly from the Conservation and Research Plans themselves.

Studies that address multiple species simultaneously can help to answer broader research questions in conservation biology.  Follow this link to a page of general research topics that could form the basis for a grant proposal or research program.

At this time, the New England Wild Flower Society cannot offer funding to support these projects. However, we are amenable to working collaborations with researchers interested in pursuing research on rare plant species. Please contact Elizabeth Farnsworth, Research Ecologist at the New England Wild Flower Society, for more information.

Species and Research Topics

1. Adiantum viridimontanum

• Investigate ecological distributions and interactions among members of the Adiantum pedatum complex. Several aspects of Green Mountain maidenhair fern's biology are poorly understood. In particular, further research is recommended to examine how members of the Adiantum pedatum complex are distributed across ecological gradients and how members of the complex interact in locations where they co-occur. Increased knowledge of the hybridization frequency between Adiantum viridimontanum and its progenitors would be useful, as would information about the factors that influence the formation, distribution on the landscape, and success of species and hybrids. Field investigations of these questions would be aided by a better description of field characters that can be used to distinguish A. viridimontanum from its hybrids.

• Research spore banking. Information about spore viability under various storage regimes is currently lacking, so the success of spore banking as a conservation action will depend on further research in this area.

2. Agastache nepetoides

• Genetic testing to determine the relationship of disjunct Connecticut and Vermont populations with each other and with other populations in the nearby range of New England occurrences

• Perform field experiments to determine annual rates of survival and reproduction for A. nepetoides at Norcross and NEWFS Garden in the Woods for their current populations and also for the extant Vermont and Connecticut populations. It would also be interesting to compare populations in which the habitat is maintained to provide open conditions with habitat that is left to ecological succession.

3. Agastache scrophulariifolia

• It is not known whether seeds are persistent and viable in the soil seed bank. A study to determine seed viablility in the soil should be conducted at stations where plants have not been observed recently. Experiments should be conducted at VT. 001 (Pownal), MA No EO Number (West Cummington) and at CT .001 (Roxbury). Competing growth should be removed to allow sunlight penetration followed by soil scarification as described in the conservation and research plan.

4. Ageratina aromatica

• Does fire do more for Ageratina aromatica than merely resetting the successional clock? Does the heat of a fire, its destruction of the litter layer, or the pulse of nutrients that follows it stimulate germination? Do any of these effects of fire alter the understory community in ways beneficial to A. aromatica after germination (such as by removing herbaceous competitors)? Or is canopy thinning by other means, including artificial ones, equally beneficial?

• Are there peculiarities in soil chemistry that are conducive to A. aromatica in New England? In Pennsylvania and Maryland, the species is reported primarily on serpentine soils. Does the soil at New England sites share some characteristics with these serpentine soils?

• Genetic analysis could reveal the relatedness of the various populations. It would be especially useful to understand the relationship among the four subpopulations that comprise MA .022 (Quincy). Is there gene flow among them, making them true subpopulations within a metapopulation structure? Is one ancestral to the others? Or are they actually independent, reproductively isolated populations? This would help explain natural patterns of dispersal and ultimately the effective size of habitat areas needed to support A. aromatica in the long term.

5. Amerorchis rotundifolia

• Are current adult plants surviving? If not, try to identify what might have changed in the habitat to decrease survival. Are new plants establishing in sufficient numbers to balance adult mortality? If clonal, what is the balance between clonal and sexual reproduction? What habitat changes are decreasing vegetative reproduction? Are seedlings or small plants present? If not, are seeds being produced? If so, is dispersal of seeds to unsuitable habitat high? Is seed predation high or seed survival in soil low? Do seeds germinate? Is survival of small seedlings low? If no seeds, are pollinators visiting the flowers? If they are, is pollen being transferred? Are individuals self-sterile? Is fruit abortion high? If there is no pollination, why not?

• Gather more information regarding pollination and potential insect herbivory. An insect survey should be conducted at Amerorchis flowering time. Insect specimens should be collected for identification purposes, and field observations should be conducted to observe what is visiting the flowers

• Determine microsite preferences of the plant. The general habitat of Amerorchis is understood to be northern white-cedar swamp, but microsite information is lacking. Is there a feature of microsite that enhances germination, presence, or survival? Other aspects that should be examined include temperature, light, mycorrhizal relations, and competition with other plants for resources.

• Mycorrhizal relationships need to be explored , and if possible, those necessary for germination should be determined. Rasmussen and Whigham (1993) present a method to study germination and development of orchid seedlings in the field, and they present suggestions for improvement on their method.

6. Aplectrum hyemale

• What environmental conditions and plant status are necessary for flowering?

• Are flowers pollinated (and by whom) and are the seeds viable?

• Is vegetative reproduction successful? Is the species truly autogamous?

• Are there specific habitat requirements, specifically for nutrients, moisture regimes, presence of mycorrhizal associates?

• How is this species affected by changes in habitat? How does it respond to disturbance such as canopy thinning or timber harvest?

• Does land use history affect where this species occurs? Most of the herbarium records are from the late 1800's or early 1900's. What was the landscape like at this time? How has it changed?
  

7. Aristolochia serpentaria

• Characterize in detail the preferred microhabitats of this plant.

• Study plant-insect interactions including herbivory, use of plants as oviposition sites by butterflies, and pollination dynamics.

8. Asclepias purpurascens

Note: New England populations of this plant are currently too small and precarious to permit manipulative studies or intensive field research. However, larger populations elsewhere in the plants' range could be studied to provide information. Among the questions that require answers are:

• What factors limit fruit set in A. purpurascens ?

• What environmental factors limit establishment and growth of A. purpurascens ? Determine soil pH, calcium/magnesium content, and moisture capacity at sites where the species occurs. Light availability should be characterized by recording photosynthetically-active radiation (PAR) above plants, preferably using time-integrated measures (e.g., Pearcy et al. 1997).

• Examine levels of competition with co-occurring plant species , possibly through thinning experiments.

• Document land-use history and indices of disturbance of these sites.

• Characterize levels of genetic variability in small and large populations outside New England and determine levels of outcrossing and inter-population exchange

9. Aster concolor (Symphyotrichum concolor)

• Determine habitat preferences. Comparisons with habitat preferences of prolific southern populations could be especially helpful. Create a model for optimum habitat on Nantucket and in New England to provide a habitat management target.

• Investigate reproductive biology. Determine whether the species is self-compatible; determine levels of reproduction in the wild; investigate its response to fire.

• Determine metapopulation status. Investigate and map the spatial configuration of all EOs; determine dispersal distances and potential for migration to existing EOs or colonization of new habitats; determine length of persistence of occurrences (sub-populations) with and without disturbance; determine the longevity of the seed-bank.

• Develop an understanding of A . concolor 's pollinators , especially their habitat requirements and range of travel in order to help determine connectivity of sub-populations.

• Investigate the role of insect herbivory and seed predation. Specifically, investigate the role of herbivory by rabbits, particularly the impact of the introduced Eastern Cottontail on Nantucket, to determine if reintroduction would be more successful in areas inhabited only by the native New England cottontail.

10. Botrychium lunaria

• Most recent studies in Botrychium (Wagner and Wagner 1981 et seqq.; Hauk 1995; Hauk and Haufler 1999) have sought to clarify taxonomic relationships. This would doubtfully be informative for the New England populations, both of which have no morphological indications that they are anything but B. lunaria s.s. It would not justify collection. Studies of population biology recently undertaken by Johnson-Groh (2000; also see Johnson-Groh et al. 2000), unfortunately require destructive sampling (digging up gametophytes) so similar studies should not be contemplated; only careful non-destructive studies such as inventorying above-ground plants (sporophytes) should be allowed.
  

11. Calystegia spithamaea

• Is there evidence of natural seedling recruitment? Neither seeds nor seedlings have been documented from any New England station, even though some populations have increased after management. It is not certain whether those increases were due to seedling recruitment or vegetative, colonial expansion. Surveys, therefore, must include thorough searches for seedlings. Additionally, methods of differentiating between shoots emerging from rootstocks and seedlings in the field also need to be developed, if possible to do so without digging up or damaging plants.

• Limits to the production of fruit with viable seeds need to be determined just as importantly as the causes of aborted fruit. Aborted fruit should be dissected and examined for insects, fungi and any other destructive agents. Hybridization with Calystegia sepium or other congenerics may be a potential cause of aborted fruit that warrants further investigation. The potential for self-incompatibility should also be examined.

• Pollinators and dispersers of Calystegia spithamaea also have not been documented . Surveys for pollinators should include nocturnal searches since it is likely that moths pollinate the flowers. Noting potential fruit and/or seed dispersers should be a part of all regular field surveys.

• Extent and impacts of herbivory need to be studied. Some populations in Maine have shown some evidence of leaf predation, possibly from insects, slugs, and/or deer, but the culprits and extent of damage needs to be thoroughly documented.
  

12. Carex atherodes

• Quantify areal extent, number of stems, and number of sexually reproductive culms for each population.

• Quantify seed production and limits to reproduction at as many populations as possible.

• Determine possible threats of invasive exotic plants at several sites.

13. Carex barrattii

• Investigate the habitat conditions that promote germination and establishment of C. barrattii, inside and outside its New England range . How these conditions might be promoted in natural populations? Many biologists who were contacted mentioned the probability that fire plays an important role in the reproductive success of the species. Study plots should be established so that controlled burning could be contrasted with canopy clearing and the end results closely monitored. Reproductive success could then be measured for the different treatments.

• Investigate the taxon's response to changing water levels.

14. Carex davisii

• Research the reproductive biology and ecology of Davis' sedge , expanding on work that has been done with other members of the genus Carex (e.g., Schütz and Rave 1999, Leckie et al. 2000, Schütz 2000 [as reported by Yatskievych, personal communication]). Focus attention on pollen dispersal, seed banking, seed dispersal, response to flooding and other disturbances, soil preferences, and effects of competition.

15. Carex garberi

• Study riverside seep habitats. Little is known either about the biology of this species or the ecology of riverside seeps. Studies contributing to the understanding of the ecology of this taxon are needed to understand the mechanisms responsible for establishment, maintenance, and dispersal of C. garberi occurrences as well as other species in the riverside seep community.

• Why is Carex garberi not found in all areas along the river shores?

• Is flooding or ice scour more important to survival of the plants?

• What is the minimum viable population size?

• Studies to quantify the genetic isolation of the Connecticut and Maine river populations would help guide conservation planning.

16. Carex polymorpha

• Study germination dynamics in the field and greenhouse. Previous investigators (e.g., Standley 1989) report little success in germinating seeds of Carex polymorpha .

17. Carex richardsonii

• Determine the predominant mode of reproduction in the field. Is most of the reproduction clonal or by sexual reproduction? The nature of reproduction has long-term consequences for its survival. One would expect that genetic diversity would decrease in small, isolated populations that are reproducing clonally over long periods of time. However, data from Jonsson and others (1996) and McClintock and Waterway (1993) suggest that relatively high levels of genetic variation do exist in clonal sedges. In a few species of Carex , genetic variation is similar to many wind-pollinated and out-crossing species. Hence, genetic diversity may still be high at these subpopulations if they are reproducing sexually. Also, monitor seeding recruitment.

18.  Carex wiegandii

• Reproductive biology: Gaining a better understanding of Carex wiegandii's sexual reproduction is fundamental to informing management and protection decisions. A primary conservation action for this sedge recommends that two populations in the White Mountain National Forest (NH .007 [Lincoln] and NH .008 [Livermore]), two populations in Acadia National Park (ME .019 [Bar Harbor] and ME .020 [Mount Desert]), and the one site in Conte Refuge (VT .006 [Lewis]) should be studied to determine the sedge's phenology, pollen viability, seed production, soil seed banking, dispersal mechanisms, and germination requirements.

• The proportion of populations occurring in dynamic habitats should be more thoroughly researched and used as a yardstick in understanding trends in the regional status of Carex wiegandii and to inform conservation and management action (A. A. Reznicek, personal communication with W. Nichols, 2001).

• Effects of timbering: Research should also address the compatibility of the sedge's continued presence with successional processes in timber harvested areas.

19. Castilleja coccinea

• Soil studies and species inventories of the extant sites should be carried out to determine whether any broad generalizations can be made about the range of soil factors that support the species.

• Determine the extent to which shading (and removal of shade) influences growth , survivorship, or recruitment of the species.

• The plant is a hemiparasite, but its host requirements are unknown . Identifying associated species might be important in developing a profile of appropriate habitat. William Moorhead (personal communication) has observed at the extant sites a suite of associated species that tend to be associated with alkaline soils. He feels that the species may be associated with seeps in soils deriving from limestone bedrock or calcareous tills. Leslie Mehrhoff (personal communication) considers associated species such as Gentianopsis crinata and Parnassia glauca to be more generally indicative of rich sites. Likewise, Linke (1980) and Smith (1983) independently report this species associated with Indian paintbrush at different sites. The work done on C. coccinea by Malcolm (1962 a, 1962 b ) and evidence from other species of the same genus (Heckard 1962, Mills and Kummerow 1988) indicates the genus is a rather generalist parasite. However, Marvier (1998) found that host quality varies and a "mixed diet" promotes the highest reproductive success while diminishing the growth of herbivores on C. wightii . Marvier and Smith (1997) discuss the potential importance of recognizing and preserving the appropriate host assemblage to the conservation of parasitic plant species. Using a list of the associated species at CT. 004 , common garden experiments should be undertaken to determine whether some hosts support greater reproductive success in C. coccinea . Host-parasite relationships may also influence germination success.

• Characterize the effects of disturbance on the species: churning of wetland soils by some type of grazing mammals was an historically important component of the Indian paintbrush ecology. Each of the two most viable extant sites has experienced some soil disturbance annually for several years: one is mowed for hay and the other was grazed until recently. Disturbance should be explored in the field to determine how it might affect the success of germination and recruitment.

• In variably sized experimental plots, Allee effects should be explored by comparing seed set between "populations" as a consequence of different plant densities. Evidence seems to indicate that pollinator availability is not limiting seed production at this site. However, Allee effects might be important in the smaller extant populations.

20. Chamaelirium luteum

• What minimum number of individuals do we need to have in a population, given a particular size and sex ratio of individuals in these populations, in order to achieve population stability within twenty years? It should be possible to use computer simulation along with the methodology and variables used by Meagher (1978, 1982) in order to predict minimum viable population size and composition. In order to perform the analysis, size-specific projection matrices could be constructed from different theoretical starting proportions and numbers of male, female, and juvenile plants. In order to build the model, a number of assumptions about survival rates and sex ratios would need to be made, but results from the North Carolina populations could be used as a starting point.

21. Corydalis flavula

• Determine whether removal of encroaching shrubs at one Connecticut site enhances survivorship, growth, and recruitment of the plants.

• Determine primary pollinators of the species in Connecticut (these may include a rare butterfly) and assess the relative contributions of insect pollination and self-pollination (cleistogamy) to reproductive success

• With four moderately secure populations in Connecticut, most of which may rely heavily on cleistogamous reproduction to set seed, it is of interest to determine: 1) the genetic relatedness among these populations and the nearest populations outside New England and 2) levels of genetic variability within populations and the ramifications of this for seed set and seedling establishment.

22. Cynoglossum virginianum var. boreale

• Research pollinator ecology and possible pollinator limitation: An experiment comparing flowers that are hand-crossed, self-pollinated by hand, and bagged to exclude pollinators should be performed to quantify pollinator limitation and out-crossing effects on seed set at either the sites in Maine or New Hampshire. In populations where pollinator visitation is believed to limit seed production, flowers should be hand-pollinated to decrease pollinator limitation due to small population size. An additional benefit is that deleterious genetic effects may be reduced by hand-crossing pollen.

23. Cyperus houghtonii

• How long can C. houghtonii seeds remain viable in the soil?

• How are the germination and establishment of this species affected by fire?

• What degree and frequency of disturbance is ideal for the sustainability of this species?

• What factors that affect seed viability?

• What factors that affect seed germination?

• What environmental or biological factors affect the fluctuation of natural populations from year to year?
  

24. Desmodium cuspidatum

• Determine degree of self-incompatibility. This could be accomplished through bagging experiments, either in the wild or on garden plants. Using garden plants will be preferable, given the small number of current populations in New England.

• Describe pollination mechanism, particularly whether a "tripping" mechanism is an essential part of pollination in wild populations.

• Identify pollinator species. This is best accomplished by observations of wild populations. At the same time, observations of any nectar robbing and concomitant bypassing of pollination would be useful.

• Quantify percentage of viable seed set in the wild. Seed collected for establishment of cultivated colonies (which may then be used for further research or for production of plants or seed for re-introductions) can be tested for germination percentages. It would be useful to know this percentage for the large populations in Massachusetts (MA 1 [North Adams] and MA 6 [Holyoke]), as well as for large populations in Connecticut and Rhode Island, if any can be located. The percentage of seed set in these apparently flourishing populations can then be compared to seed set in very small populations, such as VT .001 (West Rutland).

• Study seed dispersal. Nothing seems to be known about dispersal of Desmodium seeds in general, although adaptation to long-distance dispersal via mammalian or bird vectors is generally assumed from the seed morphology, i.e., their "sticky" outer coats. Although likely to be difficult, studies of dispersal distances in the wild, perhaps for more common co-occurring congeners, would be helpful.

• Define genets versus ramets. It is unclear how far a genet spreads in the wild, if at all. This should be determined, if only to clarify the basic population structure.

• Determine genetic structure of populations. Studies of extant populations through New England, possibly in comparison to more common congeners in New England and to D. cuspidatum populations in the center of its range, may clarify any genetic bottlenecks affecting the species in New England.

• Quantify population size variation. One current New England population (MA #1) was determined to have nine plants in 1998 and 60 plants in 2001. Assuming this was not due to differences in survey effort, this demonstrates an ability for rapid population growth. Garden plants, possibly at the Garden in the Woods of the NEWFS, should be observed to see how long it takes for a seedling to reach reproductive size and for a minimal population size to grow via local reseeding. Several wild populations should be observed annually for five to ten years each, to determine fluctuations in population size.

• Describe rhizobial interactions. New England Desmodium cuspidatum should be checked for the presence of rhizobial nodules. It would be useful to know the extent of "sharing" of rhizobial species across co-occurring legumes and other plants in each current occurrence. Inoculation of garden or greenhouse colonies of D. cuspidatum with rhizobia from flourishing wild colonies may show whether the presence/absence of specific rhizobial strains is necessary for vigorous growth of D. cuspidatum .

• Identify insect pests or susceptibility to deer browsing. Natural Heritage field forms indicate that some populations experience noticeable insect damage. The species of insect responsible, along with the extent of damage, should be observed for wild populations. While deer damage was not noted on field forms, similar observations of the extent of damage due to deer would be useful.

25. Diphasiastrum sitchense

• Special studies on clonal size, productivity and fertility are encouraged to determine growth rate, extent and possible extent of clones, and to determine optimum sustainable populations. No guidelines as to the definition or measurement of this optimum can be given at present; they should be developed by anyone undertaking such research.

26. Doellingeria infirma

• Demography - Studies should model potential population growth of this species to determine whether or not populations of the species are remaining viable in New England.

• Seed dispersal, viability, and germination - It is unknown when the species sets seed and how far the seed travels. It is hard to determine the germination rate of the species at the sites in Massachusetts, because the small population size and number of mature and flowering/fruiting individuals vary greatly from year to year. The seeds may not be viable, due either to self-incompatibility or to poor germination conditions. The possible self-incompatibility between plants of this species should be researched, as self-incompatibility will affect the genetic structure and potential growth of the extant populations. A thorough literature review of Doellingeria compatibility or lack thereof and factors effecting it is necessary to rule out the possibility of self-incompatibility in extant New England occurrences or the species itself.

• Soil seed bank experiments - It is pertinent to determine whether sufficient seeds are present in the soil; without a viable seed bank, germination in situ is limited.

• Role of Fire - Prescribed burning creates a more open habitat for this species to grow. Fire may also promote seed germination. Literature research on the role fire has played plays on related members of the Asteraceae or other rare woodland perennials would be helpful to designing experimental controlled burns. Controlled burn studies are best conducted on populations of Doellingeria infirma outside the species' New England range, as existing New England populations are small, vulnerable, and unsuited to experimentation.

27. Draba glabella

• Research seedbanking and ex-situ techniques.

• Undertake regular demographic monitoring of populations.

28. Echinodorus tenellus

• Field and greenhouse studies should be conducted to answer questions about factors influencing levels of flower and fruit production, seed viability and longevity, methods of dispersal, and specific habitat requirements (substrate and water-regime).

• An analysis of genetic variation within the extant Connecticut population should also be conducted and compared with populations in other portions of the range of the species.

• Seed storage and germination requirements should be discovered (e.g., do seeds germinate if not dried?).
  

29. Eleocharis microcarpa var . filiculmis

• Conduct research on responses of the species to mechanical soil disturbance such as that provided by ORV use. The intent of the research is to provide guidelines for managing ORV use, or substituting more controlled disturbance regimes, if mechanical soil disturbance proves to be important for population vigor. Variables such as frequency, timing and severity of disturbance will need to be evaluated. The central question that needs to be answered is: What are the effects, both beneficial and detrimental, of soil disturbance? The study should be designed to assess long-term effects at the scale of whole populations rather than small, patch-scale, short-term effects.

• Determine whether Eleocharis microcarpa var. filiculmis produces a persistent soil seedbank. If so, what is its longevity? What environmental signals promote seed germination?
  Determine whether E. microcarpa has an annual or perennial life history. Particular attention should be paid to vegetative (pseudoviviparous) propagules, in which the potential for overwintering has not been assessed. Adult plants in deeply flooded areas, which may not experience freezing temperatures during the winter, should also be examined to determine whether they survive for multiple years.

• Research dispersal mechanisms. The survival of the species in New England requires that it spread to additional stations in the local area and establish new populations further afield. Ducks and shorebirds have been implicated in the long-distance dispersal of other Eleocharis species, and establishing whether possible seed dispersers frequent the sites would be useful. Research on the effectiveness of ORVs as a seed dispersal agent is particularly needed. Controlling ORV access to occupied habitat is straightforward, giving managers a potential tool for controlling dispersal if vehicles prove effective at carrying seeds.

• Hydrology probably plays a central role in governing the distribution and local population dynamics of Eleocharis microcarpa var. filiculmis. A research project is recommended, designed to document the hydrologic regimes at MA .001 (Dartmouth) (and possibly compare this with other sites in the plant's range) and, in conjunction with population monitoring data, develop information about population response to hydrologic variables. The results from the research will help predict local population response to possible hydrologic changes, and refine our understanding of the types of natural habitats where the species might become established.
  

30. Eleocharis quadrangulata

• Explain limits to recruitment of the species in New England. In the long run, research should focus on why a species with proven dispersal ability, good seed viability, low habitat specificity, and proven ability to thrive when artificially introduced, remains infrequent. There is a bottleneck somewhere - perhaps in the "regeneration niche." Research on the influence of regeneration limitations and priority effects on constraining the expansion of E quadrangulata to new sites is needed.

31. Eriocaulon parkeri

• Determine phenology, pollination mechanisms and vectors, pollen viability, seed production, seed dispersal, and seed germination . Determining method of pollination may be difficult, as standard techniques such as emasculation and pollen exclusion bags will not work for this aquatic species without modification. Pollen viability, seed production, and seed germination studies might be expanded to explore differences in location and water quality (urban versus rural sites) in an effort to understand the declines of this species from populated areas.

32. Eupatorium leucolepis var. novae-angliae

• Initiate studies on the taxon's population biology, including reproductive methods, germination requirements, seed dispersal, and dormancy. The taxon employs unusual reproduction. Flowers lack pollen and therefore are "male-sterile" (Sullivan 1992). The plant reproduces by two asexual processes. Clonal growth is the more observable of these processes, and the dense masses of plants found on the upper shorelines of many ponds result from vegetative extensions of stolons and stems. The plant's other reproductive method is the production of viable seeds and embryo without sexual reproduction, a process known as agamospermy. How is genetic variability maintained in populations?

• Determine taxonomic status of the taxon. Sullivan (1992) suggested that, contrary to Fernald's taxonomic determination based on morphology, New England boneset is a self-sustaining hybrid between Eupatorium resinosum and Eupatorium album . She concluded that E. l. novae-angliae is not closely related to E. l. leucolepis , and proposed that New England boneset receive full species status. Wiefenbach's (1993) follow-up genetic tests ruled out Eupatorium album as a parent species, but supported Sullivan's hypothesis that Eupatorium leucolepis var. novae-angliae is a naturally reproducing polyploid taxon of hybrid origin. Her tests indicated that Eupatorium resinosum is a probable parent of Eupatorium leucolepis var. novae-angliae but that other antecedents are unknown. Wiefenbach (1993: 19) concluded that New England boneset is a paleohybrid of uncertain parentage, which originated after the most recent glaciation (10,000 years ago), and that it is "the product of a unique event from a distant time that cannot be repeated." The genetic relationship of Eupatorium leucolepis var. novae-angliae to Eupatorium leucolepis var. leucolepis requires further clarification. Conduct DNA tests that will clarify and potentially redefine the taxonomic relationships of Eupatorium leucolepis var. novae-angliae with Eupatorium leucolepis var. leucolepis and other members of the genus Eupatorium .

33. Floerkea proserpinacoides

• Demographic monitoring is recommended to detect temporal population fluctuations and identify threats that may reduce viability at certain sites.

• Invasive species effects. Specific studies need to address whether three exotic species that co-occur densely with Floerkea ? Aegopodium podagraria, Alliaria petiolata , and Ranunculus ficaria may compete with Floerkea for light, water, or nutrients, measurably reducing growth rates or fitness. Invasive shrubs and vines common to floodplains, such as Berberis thunbergii, Rosa multiflora , and Celastrus orbiculatus , can leaf out significantly earlier in the spring than native species (personal observation), potentially hindering growth and reproduction of Floerkea .

• All-terrain vehicles have been identified as a potential threat at Connecticut sites. Studies should clarify the roles of bike traffic in trampling plants, compacting soils (hampering future seedling establishment), and/or creating new, open habitat for recruitment.

• Habitat requirements. We need to better understand the floodplain habitats that currently support Floerkea in New England (and, indeed in much of northeastern North America). Are these anomalous relative to the habitat the species occupies in the rest of its range, particularly in disturbance regime? The hydrological regime and effects of floods on plant mortality, persistence, dispersal, and colonization should be characterized at all extant sites in New England.

• Exotic earthworms . While this remains speculative as a threat without further data from the sites, their presence and effects should be studied at extant Floerkea populations in New England.

• Genetic relationships among demes. It would be of interest to understand genetic relatedness of riparian populations. Such information could elucidate the sources of populations that may have been introduced among and within watersheds.
  

34. Goodyera oblongifolia

• Habitat . Knowing the size and percentage of habitat and spatial patterning within habitat occupied by Goodyera oblongifolia may provide a clearer search image for potential new populations. These features would also be important to understand for any augmentation or reintroduction efforts. It would be helpful to understand the management and disturbance histories of sites occupied by the species.

• Demography . Demographic and experimental studies may yield information regarding declining populations, and provide information critical to determining the viability of populations and a sense of minimum viable population size. It is recommended that proposed studies undergo review by a person skilled with sampling and experimental design for biological applications and with some knowledge of the site, to help assess feasibility as well as design (Palmer 1987, Hutchings 1991). Random sampling is extremely important to the validity of inferences when not sampling every individual in a population. Though experimental approaches can provide more information than monitoring (Davy and Jefferies 1981), dangers of these approaches may be greater than benefits to Goodyera oblongifolia in Maine.
  

35. Hackelia deflexa var. americana

• Study ecological interactions to determine how pollination, seed dispersal, and herbivory affect plant population structure. Quantify the species that visit northern stickseed flowers, and the resources (e.g., nectar and pollen) they take from them. Determine the frequency with which northern stickseed self-pollinates. Identify species that disperse the seeds, and describe their movement patterns. Assess the degree of genetic isolation between populations, and study the genetic diversity of these small populations. Examine the effect of herbivory on plant reproductive success. In studying all of these interactions, determine whether northern stickseed has specialized ecological relationships with any other organisms, the loss of which might jeopardize populations of the plant.

• Assess the species' response to various forms of natural and anthropogenic disturbance. Examine the kinds of substrate on which seeds germinate, and try to correlate these with disturbance processes (such as erosion of outcrops). Study whether northern stickseed favors disturbed sites because ecological competition from other vegetation is low (as suggested by Gentry and Carr 1976), or for some other reason. Determine whether human forms of disturbance, such as logging and trail use, mimic natural disturbance factors to create habitat, or destroy habitat through different processes. Trail use could be studied at VT .005 (Salisbury) and VT .009 (Shelburne). Effects of logging might be investigated at ME .003 (West Paris), VT .010 (Shelburne), and VT .011 (Milton). Given the small number of individuals in each population and the fact that the plant is rare, manipulative studies of recreational and extractive use of northern stickseed habitat would be inappropriate. Instead, workers should focus on gathering of observational data about trails and logging.

36. Hasteola suaveolens

It would be useful to know why the plant seems to flourish in cultivation, yet is declining in its natural habitat throughout most of its range. The following questions are suggested as appropriate topics of research for H. suaveolens :

• What is the relative importance of sexual reproduction versus vegetative propagation to the persistence of populations?

• Is H. suaveolens self-incompatible and is the number of compatibility groups in our populations small enough to limit seed production?

• Is a lack of suitable pollinators responsible for low seed set in our populations?

• What are the conditions that promote germination and establishment of H. suaveolens ? How might these conditions be promoted in natural populations?

• Which life history stages are most important to limiting population growth of H. suaveolens ?

• What are the consistent ecological differences between the site where the New England population occurs and the sites of large, healthy populations in other states that could account for the difference in population size?

37. Hieracium robinsonii

• Persistence and life history of individual plants. It is not clear whether it is perennial, biennial, or a monocarpic perennial. The timing of seed germination - spring vs. fall - is also not known. If plants are short-lived and germination rates are low, several years of adverse conditions could potentially extirpate the population. Adult plants need to be marked after flowering and fruiting to determine whether the same plants persist the following year(s). Can they survive ice scouring if it is present? Seedling recruitment should also be studied.

• Genetic studies would be useful in determining whether the species is showing any signs of inbreeding depression, which could lead to the eventual decline and extirpation of the population. Chromosome counts from immature pollen should be obtained. Methods are outlined in Ruzin (1999). More detailed molecular studies might be useful for determining whether Hieracium robinsonii and Hieracium ungavense are separate species if they have the same chromosome numbers.

• Pollination . If the plants depend on pollinators for seed set, it would be useful to know which species perform that role.

• Since the species is also rare in Canada, collaboration and communication with conservationists and researchers there is important and a potential source of more information on biology, habitat requirements, and threats. Demographic comparisons with Nova Scotia populations would be valuable as well.
  

38. Hydrastis canadensis

Recent studies of Hydrastis canadensis have been done regarding its status in Canada, cultivation, and pollination (Davis and McCoy 2000, Sinclair and Catling 2000a, Sinclair and Catling 2001). These studies could prove useful in modeling similar studies for New England.

• Seed germination. Attempts by the New England Wild Flower Society at getting seed to germinate have not met with success; however, other researchers have been able to grow Hydrastis canadensis from seed. New techniques regarding seed germination should be studied and applied.

• Study the effects of various habitat treatments that simulate forestry practices such as canopy thinning. Does providing more light encourage recruitment, growth, reproduction?

• The investigation of seed dispersal and potential limiting factors is recommended.

• Investigations should also be aimed at studying population size with respect to sexual reproduction and good seed set.
  

39. Hydrophyllum canadense

• Develop a consistent, efficient, and minimum-impact monitoring technique to accurately assess population sizes and trends over time while minimizing potential negative impacts such as trampling plants and damaging the habitat during sampling. It will be informative to use some combination of counting plants and mapping the locations of concentrations of the plants. It will be important to determine the most practical and accurate way to count plants. Currently, stems, clumps, and plants have been used to describe the plants; this likely results in counts that are not comparable. Ideally, a standardized sampling regime should be established for all of the populations using one measure.

• Determine optimal light, moisture, and nutrient levels for the species.

• Determine the relative importance of sexual and asexual reproduction.

• Determine the impacts of exotic invasive plant species and means of controlling them.

• Determine the role of disturbance (e.g., flooding and ice scouring) in the population ecology of the plant; determining the nature of herbivory seen in populations.

• Determine the impacts of various current land uses and investigate land use history and its impact on populations.

40. Hypericum adpressum

• Determine the ecological significance of the two growth forms. Some populations of Hypericum adpressum are characterized by robust plants with spongy stems and thickened bases, called forma spongiosum . In general, typical H. adpressum appears like an annual plant, with population numbers fluctuating from year to year based on the depth of water and consequent degree of pond shore exposure at particular sites. In contrast, the spongiose form of H. adpressum occurs as one component of relatively persistent emergent plant communities that develop in the littoral zone of ponds that do not undergo significant annual water level fluctuations. In the first situation (typical H. adpressum ), populations are dependent on unpredictable and highly fluctuating water levels that result in ephemeral shoreline exposure. In the second case (form spongiosum ), populations persist and remain relatively unchanged over the course of many years. Thus, conservation strategies must be adapted to the particular ecology of the subject habitat. One particular biological question regarding the conservation of H. adpressum concerns the taxonomic and ecological significance of the two forms of this species: typical adpressum and the form spongiosum. Although it is assumed that the morphological differences between these two forms are due to environmental factors (stability of water level and degree of immersion), it is possible that genetic variation may also be indicated.

41. Juncus vaseyi

• Identify the potential requirements for establishment, growth, reproduction, and dispersal. All extant sites should be visited during periodic monitoring for collection of ecological information that might include: substrate type, soil texture, soil pH, soil temperature, local hydrology, aspect, elevation, associated species, percent cover woody species, and local microclimate.

42. Liatris borealis

• Further investigate the role of seed predators. Clarify the relationship of L. borealis and seed predating microlepidopteran moth species. Continue work of Dr. David Wagner (University of Connecticut) on rearing out larva collected from L. borealis seed heads. Of particular ecological importance and interest is the previously unknown tortricid species that may be an obligate feeder of L. borealis . If this is the case, the fate of this insect species will depend on the fate of its host plant.

• Investigate geologic habitat preferences. Take soil samples from sites throughout the range and analyze to make generalizations about required soil types. The existence of soil preferences could also be examined by using soil maps. Populations can be located, via Global Positioning Systems (GPS) or traditional techniques, on geologic maps. These maps can be used to search for soil and other geological patterns in habitat preference. A GIS data base, which is updated with information from monitoring every 1 to 5 years, would be beneficial to conservation of this plant for many reasons. Such a database would enable assessment of trends by area in extirpation, habitat type, geologic preferences, and other important characteristics.

• Test for presence and longevity of a seed bank.

• Determine reproductive age and life expectancy. Basic life history characteristics are not known about L. borealis , and this information is valuable in assessing the health of a population. Individual plants should be tagged and followed throughout their life cycle to determine reproductive age and life expectancy of this species. These data can be obtained as part of the demographic studies recommended above.

43. Linum sulcatum

• Develop a detailed habitat-use model for Linum sulcatum in New England . An effective model for Michigan populations of L. sulcatum was constructed using surface geology, soil characteristics, aspect, and associated vegetation (Cleveland 1997). A similar model could be developed for New England and adjacent New York that uses information on the two Connecticut and eight New York populations.

• Conduct research on reproduction and population biology of the species. Research should be conducted to determine if the rarity of Linum sulcatum is caused by limitations to its reproductive output. It is unknown if the majority of seeds are viable, what species pollinate it in the Northeast, if the species is effectively pollinated, and if the species is self-compatible. It is likely that L. sulcatum is limited by available habitat in New England, but no studies have determined whether the plant might also be limited by ineffective seed production.

• Seed collection and germination tests. Seeds should be collected from the Connecticut sites from populations when they exceed 100 plants. No more than 10% of fruits produced at any one site should be collected during any year.
  

44. Listera auriculata

• Identify possible habitat; to discover dispersal mechanisms (e.g., tolerance of seeds for water dispersal and effectiveness of wind as a dispersal agent for short-statured plants); to determine how big an area can support a metapopulation (so we can comfortably decide to protect a certain size of preserve); and to develop a template to guide searches for new populations.

45. Listera australis

Given the fragility of the habitat of Listera australis , it would be hard to justify the impacts of research on small fringe populations. Habitat, climate, and morphological differences in different parts of L. australis range might mean that research done in the south, where it is less rare, would be inapplicable to northern sites. Also, North American Listera species have resisted efforts to cultivate them (Correll 1950, Rasmussen 1995).

• How do seeds disperse from disjunct northern populations into adjacent habitat? One method of tracking long-distance dispersal of tiny orchid seeds involves using molecular genetic markers to compare allele frequencies among different populations, to see which are the most likely source populations. Other methods, such as irradiation of seeds, might be useful to track short-distance dispersal (Wang and Smith 2002).

• What conditions are necessary for germination? Does it need small disturbances to germinate, or an unbroken carpet of peat moss? Rasmussen and Whigham (1993) have described a way to study in situ germination that might be useful for L. australis. Tiny orchid seeds are sown in packets that retain the seeds while allowing access to soil fauna and water. The packets are buried and tethered to a pole for easy retrieval. This method could provide data on dormancy period, seed mortality, germination conditions, and the fungi that associate with seedlings.
  

46. Listera convallarioides

• Characterize L. convallarioides preferred habitat. Studying populations in states where the orchid is not rare (e.g., Vermont, Maine) might help answer these questions: What type of habitat is most likely to harbor populations? How does slope, with its effect on water velocity and hence substrate and water depth, affect populations? What range of water pH, alkalinity, and temperature does L. convallarioides enjoy? How is it dispersed between patches of habitat? Does it need perennial water or can it tolerate dry periods? Hall et al. (2001) found that environmental influences that correlated with plant species in a seep are pH, concentration of major ions, percentage of open water, and substrate height above the water table. Although growing conditions for northern white cedar are fairly well defined (Johnston 1990, Sperduto and Engstrom 1998, Thompson and Sorenson 2000), the microhabitat for L. convallarioides could use clarification.

• Study pollination. It would also be useful to discover whether L. convallarioides has a variety of pollinators, to rule out dependence on a single, perhaps vulnerable, insect. More knowledge about the fungus that sometimes attacks L. convallarioides might let us know whether it affects long-term survival of a population.

47. Listera cordata

• We need to characterize the microhabitat preferences of the plant in the New England sites where it occurs. Although the plant grows in dry duff in the west, in the northeast the species appears to prefer habitat that is at least seasonally moist. It would be of interest to gather information on moisture regime (perennial or seasonal), pH of water and soil, and light availability for populations where it is relatively common, for example Maine and Wisconsin, in addition to New Hampshire.

48. Ludwigia polycarpa

• Study the hydrological requirements of the species and its habitat.

• Study the relationship between light levels and occurrence and vigor of individuals and populations.

• Study life history components and determine potentially vulnerable stages in the life cycle.

49. Ludwigia sphaerocarpa

• In light of growing demands for water withdrawal within its coastal plain habitat, the most critical information needed in terms of long term management is L. sphaerocarpa's response to water level changes, both natural and artificial. By investigating historic water level fluctuations for existing stations, it may be possible to determine the range of tolerance for water level variation. Any field investigations along this line should also note the relationship of other rare plant species to water level fluctuations/manipulations.

• Additional information on population demographics is also desirable. Data confirming the growth patterns and vigor of populations in sheltered versus exposed micro-habitats would contribute to the tailoring of future conservation actions.

50. Mimulus moschatus

• Survey for historic occurrences. In addition to the above extant occurrences, there are two historic naturally occurring populations in Deerfield and Orange, Massachusetts. Efforts to find these occurrences should be pursued. Locating these occurrences would be important in extending the geographical distribution of the species. There are also reports of undocumented populations in northern Vermont, which should be researched and surveyed.

• Collect basic demographic data on existing populations.

• Perform a morphological analysis (possibly complementing a genetic analysis pending other, larger funding sources) of the affinity and relatedness of New England and western populations of Mimulus moschatus.

51. Moehringia macrophylla

• How does canopy openness influence growth and reproduction? Low light availability due to growth of perennials and canopy closure at several sites has been suggested as a possible cause of population decline. On the other hand, plants at one occurrence tend to fruit more successfully in shady, moist conditions. The effect of canopy openness on growth and reproduction needs further investigation. Protocols should include a combination of greenhouse studies and controlled field experiments at sites such as the three listed above. In the field, light levels could be manipulated by removing vegetation and/or constructing artificial shade. Marked clumps in experimental and paired control plots should be monitored for at least three years, since effects may not be immediate. Parameters to monitor include flower production, fruit production, vegetative growth (height and number of stems), seedling production, soil moisture, and light availability.

• What are the principal causes of decline for populations in New England? Research to determine the cause of decline at the two sites (CT .001 [Guilford] and CT .002 [Durham]) where this has been well documented should be a priority. Possible causes to investigate include trampling, water stress, lack of recruitment, forest clearing, and change in light availability.

• Does reproduction occur primarily through outcrossing or vegetative increase?

• How do pollinators and seed dispersers influence population growth?

• Herbivory, disease, and parasitism are all poorly understood for this species and could merit further study.

• Long-term demographic studies could help to determine whether seed production, germination, and/or seedling recruitment are limiting factors, and whether population growth occurs primarily by sexual reproduction or vegetative increase.

• Seed dispersal should also be investigated. In habitats such as rocky outcrops it is particularly important to have a dispersal agent that can move seeds to favorable sites for germination and establishment. Simple observation could help to determine whether large-leaved sandwort seeds are indeed dispersed by ants, which species distribute the seeds, and how abundant ants are at sites in New England. To investigate how the ants aid germination and establishment, ants could be censused during periods of seed availability for comparison to counts of seedlings and young plants in subsequent years.
  

52. Nabalus racemosus

• Disturbance ecology. An interesting note for Nabalus racemosus is that it also occurs in prairie situations. Spring fire has been found to increase flowering in N. racemosus in certain prairie populations (Pemble et al. 1981 in Collins and Wallace 1990); perhaps ice scour acts in a similar fashion.

• Life history. Field studies in Maine would shed some light on the number of years it takes Nabalus racemosus seedlings to establish, and what factors inhibit or enhance survival.

• Community ecology of the calcareous rivershore seep community.
  

53. Nabalus serpentarius

• Study seed dispersal, viability, and germination. The distance over which seeds are dispersed is unknown. Poor germination has been observed at the New England Wild Flower Society. Either the seeds are not viable due, perhaps, to self-incompatibility, or the correct germination conditions are not known. If populations are to be increased in size, a large supply of plants would be required, so ability to germinate and raise the seedlings will be an essential first step.

• Determine dynamics of soil seed bank and survival of seedlings. If this species is monocarpic, the persistence of these populations will depend on the presence of sufficient seeds in the soil. The lifetime of the seeds in the soil seed bank, the percent germination of the seeds, and the percent survival of seedlings will provide information on the viability of the populations and the need for augmentation or introduction.

• Study potential self-incompatibility. Many Asteraceae tested to date have sporophytic self-incompatibility. No information exists on the genus Nabalus . If the species is self-incompatible, populations must exceed a critical size to maintain sufficient S alleles to permit successful reproduction (Byers and Meagher 1992). Some small populations of Asteraceae have evolved self-compatibility in response to strong selection at reduced population size. Experiments should compare seed set in self-pollinated and cross-pollinated individuals. Individuals from various New England populations should be crossed to determine S allele diversity if self-incompatibility is found. For example, see the experiments performed by Reinartz and Les (1994) and Byers (1995).

• Characterize growth habit. Although Nabalus serpentarius is generally considered a perennial, observations indicate that the species is monocarpic and dies after flowering. Confirmation of these observations is needed, and can be obtained by closer observation of existing populations over several years. Small populations of plants that are short-lived and do not reproduce vegetatively are at greater risk of extinction than perennials or colonial plants (Fischer and Stocklin 1997) and have larger minimal viable population requirements than perennials and species with vegetative reproduction (Pavlik 1996).

• Quantify demography. It is not known whether the existing populations are growing or declining. Such information is required for a population viability analysis.

• Describe the role of fire in relation to the plant. The largest population of Nabalus serpentarius in New England grows in a habitat, sandplain heathland, adapted to fire (Barbour et al. 1998). Burning might simply provide open habitat for this species, but fire could play a role in the biology of the species, perhaps by promoting seed germination, and ex situ experiments to determine the role of fire in germination should be performed.

54. Neobeckia aquatica

• Investigate the demography of fluctuating populations.

• Determine critical life stages that may be influencing population fluctuations.

• Determine physical factors that may influence population fluctuation. Studies of habitat preferences -- namely, pH requirements, optimal light regimes, and requirements for sediment composition and nutrient levels -- should be undertaken.

• Determine biotic interactions that may influence population fluctuation . Biological interactions, including potential herbivore interactions and the existence of symbiotic relationships, should be documented.

55. Oxalis violacea

• Effects of shading. Does the closing of the canopy (shading) lead to reduced flower production? Does shading lead to increased emphasis on asexual reproduction and/or decrease of population size?

• Reproduction . Can both pin and thrum flower forms be found in New England populations? If not, then in the absence of one of the flower morphs, are seeds being set? Are flowers self-incompatible, as reported from another part of the range? Pollinators have been studied in the Midwest, but studies of pollinators in New England were not found.

• Seed ecology. How many seeds are produced per capsule? The Missouri Flora Website (2002) informs us that the capsules elastically dehisce from vertical sutures. Seeds of the congener Oxalis acetosella are discharged, traveling up to a meter horizontally (Packham 1978); are seeds of O. violacea also ejected? After release from the capsule, are seeds further dispersed by flowing water (for example from torrential rains), and are animals responsible for long-distance dispersal? How long do seeds remain dormant?

• Effects of fire. Do prescribed burns stimulate seed germination and renew population vigor? Dormant versus growing season prescribed burns could be compared.

• Simulation of fire . Can fire be simulated by the clearing of undergrowth and canopy thinning? Does fertilizer also have to be applied to accurately simulate fire? Given that increased frequency of burns can be positively correlated with significant increase in soil pH (Tester 1989), should lime be applied to simulate the long-term effect of repeated burns? Does simulation of fire lead to renewed population vigor?
  

56. Oxytropis campestris var . johannensis

• Range-wide morphological study of yellow locoweed to determine distinctiveness of the numerous varieties. The objective of the biosystematic study would be to determine taxonomic validity of St. John River oxytrope. The objective should be considered completed when the null hypothesis that no difference exists between Oxytropis campestris var. johannensis and other formally recognized varieties of Oxytropis campestris is accepted or rejected. Part of the study would consist of obtaining chromosome counts for varieties of yellow locoweed. Also, Molecular evidence should be used to provide an independent data set for subspecific taxonomic analysis of yellow locoweed.

• A reproductive biology study (e.g., aspects of pollination, seed germination requirements) should be performed to assist in delineating varieties of yellow locoweed and provide useful information for conservation activities.
  

57. Panicum flexile

• Study ecological interactions to determine how seed dispersal and herbivory affect plant population structure.

• Assess the plant's response to natural and anthropogenic disturbance.

58. Paronychia argyrocoma

• Identify pollinators in at least three separate locations, one montane, one along the Saco River, and the Massachusetts site.

• Study limiting factors influencing dispersal, germination, and establishment of successful reproductive populations would be valuable.

59. Pedicularis lanceolata

• Study demography. At this time, no population viability analysis of Pedicularis lanceolata has been performed, and so it is difficult to state specific, quantitative conservation objectives for population sizes and numbers of this taxon with any degree of confidence. Because P. lanceolata is short-lived, is not self-pollinating, and is relatively late-flowering, large populations may be required in order to maintain viability. Turnover rate in short-lived species is greater than that in longer-lived species, and so more plants are needed to allow for yearly fluctuations in survival rates. Species that are not self-pollinating require enough other individuals within traveling distance of pollinators to achieve pollination and seed set. Finally, plants that are insect-pollinated and are late-flowering may need to be present in enough abundance to meet the nutritional requirements of pollinators without help from many other species.

• Studies of another species of Pedicularis can provide some insight into the issue of population size. A species with similar habitat requirements and life history, Pedicularis palustris , inhabits "fen meadows" in Europe (Schmidt and Jensen 2000) and wet soil in eastern Canada (Gleason and Cronquist 1991: 487) and is becoming rare in some European countries. Like P. lanceolata , it is short-lived and is primarily out-crossing (Macior 1993). In a single-year examination of 13 extant populations in Germany and Norway, populations were shown to be highly variable, having between three and 28,500 flowering individuals each (Schmidt and Jensen 2000). In this species, larger populations were correlated with higher numbers of capsules per plant and with higher numbers of seedlings per flowering plant.

• Perform demographic studies of occurrences in parts of the country where it is not endangered and to compare these with New England populations. Potential differences in climate, vegetation, and pollinators must be considered when applying results of such studies in New England.

60. Polemonium van-bruntiae

• Quantify germination rate and seedling survival rate (some data already exist from a previous introduction of plants into a new site in Vermont)

• Characterize demography (e.g., percent of new stems in a population per year, average age of individual plants and age structure of population, average age and range of ages at reproductive maturity, average and range of number of seeds set, and average lifespan), the size of clones and the genetic structure of populations (e.g., average number of ramets per genet and genets per population); following marked individuals would be helpful, and data obtained might allow researchers to model population viability.

• Determine pollinators and pollination success (while bees have been observed visiting some flowers, very little is documented about Appalachian Jacob's ladder pollination); percent seed set, and mechanisms of dispersal; understanding these may be especially important for managing small populations, like the one in Maine

• Study habitat requirements (e.g., why is it rare, if it grows well in roadside ditches?), especially light, tolerance for flooding and drought, and soil pH and nutrient profile

• Document effects of disease and herbivory

• Genetic study. This plant has an unusual distribution, with several occurrences in Vermont, and one disjunct population in Maine. A genetic study could elucidate the origin and degree of isolation of this population, and enable us to determine whether conservation is warranted or feasible at this edge-of-range occurrence.

61. Polymnia canadensis

• Research species ecology in New England. Recent studies of Polymnia canadensis have been done regarding life history, germination, and pollination (Bender 1991). These studies could provide a model for similar studies in New England. Of particular interest may be a study of dispersal and seedling requirements. It remains puzzling as to why so few sites exist in New England where suitable habitat does not appear to be a limiting factor.

62. Populus heterophylla

• Effects of canopy and sub-canopy thinning on flowering, pollination, seed production, seedling recruitment, vegetative reproduction, and growth of Populus heterophylla ; special attention should be given to possible effects on other woody species, particularly potentially invasive trees, shrubs, or vines

• Sex ratio, age structure, reproductive health, and other factors influencing effective population size in existing populations of Populus heterophylla

• Genetic variation , both within and between the New England populations of Populus heterophylla

• Application of various methods for ex-situ propagation of seeds, seedlings, and cuttings of Populus heterophylla taken from local populations and, if successful, carefully monitored experiments in introduction, reintroduction, and/or augmentation of existing populations with propagated cuttings

• Use of geographical information system technology to identify potential habitat for Populus heterophylla in southern New England

• Edaphic, hydrologic, and mycorrhizal factors and their influence on occurrence and growth of Populus heterophylla

• Application of Population Viability Analysis to extant populations of Populus heterophylla in New England to project the future status of the species and of each population and to assess possible consequences of various conservation options; this task will require genetic and demographic data obtained from empirical investigations described above.
  

63. Potamogeton ogdenii

• Water quality should be tested at regular intervals. Suggested chemical tests similar to those conducted by Hellquist (1975, 1980) could be pH, total alkalinity, carbon dioxide, chlorides, nitrates, phosphates hardness, and conductivity. Tests should follow standard methods such as outlined by Lind (1985). Water chemistry often determines which species occur in a given body of water (Moyle 1945, Hellquist 1975, 1980, Hutchinson 1975). The information gathered will help establish the parameters for P. ogdenii. This is important since only limited data for this taxon have been gathered. This information will also be useful in searching for new populations in lakes and ponds with similar water chemistry, especially total carbonate alkalinity.

64. Potamogeton strictifolius

• Water quality should be tested when surveying the known sites for plants . Suggested chemical tests similar to those conducted by Hellquist (1975, 1980) could be pH, total alkalinity, carbon dioxide, chlorides, nitrates, phosphates, hardness, and conductivity. Tests should follow standard methods such as outlined by Lind (1985). Water chemistry often determines which species occur in a given body of water (Moyle 1945, Hellquist 1975, Hutchinson 1975, Hellquist 1980). The information gathered will help establish the parameters for P. strictifolius . This information will be useful in searching for new populations in lakes and ponds with similar water chemistry, especially total carbonate alkalinity. If nutrient-loading is detected, possible sources should be searched for.

65. Pterospora andromedea

• Collect data on phenology, size of inflorescences, spacing of inflorescences (do they appear in "clumps"?), herbivory, seed production and dispersal, persistence or reappearance of individual plants at exactly the same location, and pollinator visits. Pollinator identification is likely a crucial piece of missing information. Observation of fungal associations will also be vitally important.

• Analyze any and all available records of historic occurrences to shed light on the causes of Pterospora 's decline in New England and almost complete disappearance in New York. The broader the area of study, the more likely it will be to yield evidence of causative factors, so, ideally, records for the entire eastern population segment (from Michigan to Prince Edward Island) should be examined. Wherever possible, field notes or publications of collectors should be reviewed for any information about the occurrences they collected. Mapping of historic occurrences and last observation dates, when compared with land use history, could be especially informative. Knowledge gained about causes of Pterospora 's decline in the East may help in formulation of strategies for its recovery.

• Conduct wider sampling and DNA analysis of Pterospora and its associated mycorrhizae from sites throughout the eastern distribution to determine which Rhizopogon species are parasitized by eastern lineage(s) of Pterospora . Introduction, reintroduction, or augmentation of Pterospora undoubtedly would require the presence of adequate populations of the appropriate species of Rhizopogon mycorrhizal fungi at the chosen site. The genus is taxonomically challenging (Kretzer et al. 2000, Bidartondo and Bruns 2002), and very little is known about the distribution of Rhizopogon species, especially in the East.

66. Ranunculus lapponicus

• Habitat . The microhabitat of Ranunculus lapponicus is understood to be wet hollows in northern white-cedar swamps, but specific microsite information is lacking. Is there a feature of this microsite that enhances germination, presence, or survival? Other microsite aspects that should be examined include temperature, light, possible mycorrhizal relations, and competition with other plants for resources. Determination of associated vascular and bryophyte species can occur during inventory efforts at those occurrences where that information is lacking.

• Experimental canopy thinning. If a correlation is noted between certain light levels and some aspect of Ranunculus lapponicus performance, experimental manipulation of the habitat at several Maine sites could occur. Ranunculus lapponicus is typically considered a species of the deep shade of northern white-cedar swamps, but one of the larger patches is near a sizeable canopy gap (personal observation). Experimental cutting of one or a few trees could help determine if moderately increased light levels are beneficial to R. lapponicus. Cutting done in winter would have less impact on the habitat of northern white-cedar swamps than other harvest techniques (Carlson and Sweeney 1999).

• Population viability analysis. Understanding the relationship between numbers of Ranunculus lapponicus individuals (and possibly their reproductive vigor) and the percentage of available habitat they occupy at each site will likely help us to determine a realistic goal for the number of individuals at the smaller sites and the number of individuals to utilize for outplantings into low population number sites.
  

67. Rhexia mariana

• Collect data on the population structure, life history, reproductive and dispersal abilities, and habitat requirements of this species in New England to inform future conservation decisions. Is Rhexia mariana limited primarily by abiotic factors such as temperature, moisture, or soil nutrients, or by competitive interactions with other plants? What are the competitive abilities of this species? Which other plants are most likely to interfere with its growth? How do changes in water levels on pond shores affect the health of R. mariana populations and its competitors? Is pollen limitation a problem for the reproduction of this species as it was for R. virginica in Ontario?

• Are the extant populations on Cape Cod are genetically independent or form one or more metapopulations? This information would help determine where introductions would be most beneficial and which would be the best sources for seeds. Two extant EOs in Sandwich are about 0.5 km apart, and five EOs in Brewster are each no more than 2 km from one of the others, with one pair within 0.6 km and the other three within 0.8 km of each other. Bumblebees occasionally range as far as 5 km from their nests (Heinrich 1979, Goulson and Stout 2001), but a study of Rhexia virginica populations in Ontario implied little genetic exchange between populations only 400 m apart when separated by an arm of a lake (Larson and Barrett 1999a).

• It may also be informative to make genetic comparisons between New England representatives of the taxon and those from the center of its range to determine if this peripheral population is evolving differently from the rest of the species. Is there a genetic basis for the apparently narrower habitat requirements of R. mariana in New England? Any research that could help explain why the very similar Rhexia virginica is so much more common on Cape Cod and extends farther north to Nova Scotia and Ontario would also be useful.

68. Rhynchospora capillacea

• Competition experiments may inform future management activities , because competition is one of the primary threats to this species. Of particular interest would be competition with other native calcareous wetland species, such as Carex lasiocarpa , which is present in many fen communities, and which increased in cover following water level rises caused by beaver damming (Rawinski and Lapin 1990).

• Research into population