29 



C. DESCRIPTION 



1. GENERAL NONTECHNICAL DESCRIPTION: This small, 

 slender annual is usually less than 12 (18) inches 

 tall. The herbage may be smooth to somewhat 

 sparsely stiff-hairy, especially at the margins of 

 the leaves and angles of the stem. Distinctive 

 sharply toothed, roundish leaves, with squared off 

 bottoms, clasp the stem alternately at short 

 intervals. Tiny, blue, five-lobed flowers are 

 found in the leaf axils, but most are early 

 deciduous. 



2. TECHNICAL DESCRIPTION: Lax, very slender, simple 

 or sparingly branched annual, commonly 0.5-3 dm. 

 tall; herbage glabrous, or not infrequently hispid 

 on the margins of the leaves and angles of the 

 stem; leaves somewhat clasping, distant, rotund or 

 rotund-ovate, sharply toothed, small, seldom as 

 much as 1 cm. long; calyx divided to the 

 hypanthium, the lobes foliaceous, veiny, ovate or 

 broader, 2-4 mm. long; corollas of the upper 

 flowers blue, 3-6 mm. long, the others abortive; 

 hypanthium commonly spreading-hispid (Hitchcock et 

 al. 1955-1969) . 



3. LOCAL FIELD CHARACTERS: This tiny annual is 

 distinguished by rotund, toothed leaves, which are 

 abruptly squared off along the bottom where they 

 clasp the stem. A line drawing of H. rarif lorum 

 is presented in Figure 4, p. 33. 



D. GEOGRAPHICAL DISTRIBUTION 



1. RANGE: Heterocodon rariflorum populations range 



from southern British Columbia to California, east 

 to Nevada, Idaho, Wyoming, and Montana. 



In Montana, where this species is on the periphery 

 of its range, it is known from the Bull River 

 valley, Sanders County (2), from the Bitterroot 

 Mountains, Ravalli County (1), and from one 

 historical record in Lake County. A map 

 indicating the distribution of this species in 

 Montana is presented on p. 34. 



Information on the surveys of populations in the 

 Bull River valley is presented on pp. 35-36 

 (Element Occurrence records) . The location of 

 each population is marked on U.S.G.S. maps, pp. 

 37-38. 



