obovate. In addition, the flowers of C. heterophvlla are 

 axillciry, very inconspicuous, and do not have a corolla. 



D. Identifying characteristics of material vihicti is in interstate or 

 international oannerce or trade: No interstate or international 

 conmerce or trade kncwn. 



E. Photographs and line drawings: Figure 1 provides a copy of the 

 illustration of this species, adapted from Meinke (1982) . Ihe 

 color slides (p. 8) are duplicates of those taken at the sites 

 indicated. Additional slides frcxn other locations in Montana 2u:« 

 housed at the MINHP office in Helena. 



4. SignificEmoe. 



A. Natural: As a inonotypic genus, tJ- aouatilis is taxoncmically 

 unique. The only genus which seejns closely related to Hcwellia 

 is Leqenere . The latter is also inonotypic, consisting only of 

 the species i,. lijTOsa . and occurs in dried bods of vernal pools 

 in the Central Valley of California (Munz 1959) . Recent 

 electrophoretic studies (Lesica et aJ. 1988) indicate that there 

 is no genetic variation either within or among populations of H. 

 aquatilis ; this is also unique, especially considering its wide 

 geographic distribution pattern. However, lack of genetic 

 variation is often correlated with the narrcM ecological 

 anplitude possessed by species such as U- aquatilis (Waller ££ 

 fll. 1987) . Howell ia aquatilis has thus provided a valuable 

 subject for conservation biology stixiies. Otherwise, the species 

 is not known to have any peculiar adaptations or strvictures, or 

 roles in stabilizirq landfoms. Obligate relationships with 

 other species 2une unknown. 



B. Hunan: As discussed, \i. aquatilis would be of scientific 

 significance in studies addressing its systematic relationships 

 and isolation, and has been an important subject in conservation 

 biology reseeuxh. Otherwise, the species has no known 

 agricultural, economic, horticultural, or other human uses or 

 significance at this time. 



5. Geogrz^ihical distribution. 



A. Geogre^iiical range: Hcwellia acaaatilis is currently )ax3wn from 

 a total of 13 sites: one in Idaho (Latah County) ; three in 

 Washington (Clark and Spokane counties; J. Gamon, pers. conn.); 

 and nine in Montana (Lake and Missoula counties) . It is 

 historicadly kncwn from one collection in California (Mendocino 

 County; Smith and Berg 1988) , four locations in northwestern 

 Oregon (Clackamas, Marion and Multnomah counties; S. Vrilakas, 

 pers. conn.), cne location in Washington (Mason County; J. Gamon, 

 pers. conn.), and one collection from northern Idaho (Kootenai 

 County) . Ihe range is indicated in Figure 2, p. 9. 



