This chapter summarizes the distribution of the seven species that were 

 previously listed as endangered or threatened in Maine. Geographic ranges, 

 preferred habitats, reproductive characteristics, taxonomic status, 

 interrelationships with other plant and animal species (i.e., pollinators), 

 and the major human-related threats to these species are discussed for each 

 taxon. The rare species are discussed as a group. Rare and unusual plant 

 communities containing three or more rare plant species are also described. 

 Factors affecting abundance and distribution of plants are discussed 

 generally, and data gaps and management problems are summarized. The 

 approximate locations where endangered, threatened, or rare plants are known 

 to occur in coastal Maine are indicated on atlas map 4. Common names of 

 species are used except where accepted common names do not exist. Taxonomic 

 names of all species mentioned are given in the appendix to chapter 1. 



DATA SOURCES 



Lists of endangered, threatened, and rare plants (table 20-1) were obtained 

 from the Federal Register (16 June 1976), the Smithsonian report (Ayensu and 

 DeFilipps 1978), the Critical Areas Program of the Maine State Planning Office 

 (Eastman 1978a), and the New England Botanical Club (Eastman 1978b). Data on 

 the distribution of these species in Maine were gained from the Critical Areas 

 Program (planning reports, botanical fact sheets, and unpublished data), 

 published literature (Schuyler 1974; Rand and Redfield 1894; Wheary 1938; Wise 

 1970; and Fasset 1928) and herbarium specimens (Eastman 1978a; and the Academy 

 of Natural Sciences of Phildadelphia) . 



Data on the geographic ranges, preferred habitats, growth habits, and 

 longevity of these species were obtained from Fernald (1950) and Gleason and 

 Cronquist (1963). Information on reproductive biology, including pollinators, 

 came from published literature and personal communications with specialists. 



ENDANGERED AND THREATENED PLANTS 



Of the seven species of endangered or threatened plants in coastal Maine, the 

 ram's-head lady' s-slipper ( Cypripedium arietinum ) , auricled twayblade 

 ( Listeria auriculata ) , pale green orchis ( Habernaria f lava var. herbiola ) , and 

 ginseng (Panax quinquefolius) are considered true species by plant 

 taxonomists, and further research into their distribution and abundance is 

 warranted. The taxonomic status of Orono sedge ( Carex oronensis ) , Long's 

 bitter cress ( Cardamine longii ) , and estuary monkey flower is less certain. 

 Orono sedge is a member of a genus whose species are difficult to distinguish. 

 Long's bitter cress and the estuary monkey flower may be only ecological races 

 and not worthy of taxonomic recognition. Available biological information on 

 these species in coastal Maine is summarized below. Little information is 

 available on most of these taxa . 



The Estuary Monkey Flower 



The estuary monkey flower is a member of the snapdragon family and is 

 apparently an ecological variant of the more common M. ringens var. ringens . 

 The coastal variety is restricted largely to the upper intertidal zone of 

 estuaries in Maine and the St. Lawrence River estuary in Canada. The more 

 common variety ( ringens ) is abundant in wet meadows and along the banks of 

 streams throughout Maine. At least one specimen of this variety has been 



20-10 



