150 LEGUMINOSAE. 



beneath, about 2 cm. long; tendrils well developed; stipules deeply toothed; 

 peduncles usually shorter than the leaves, 4-8-flowered; flowers purple- violet, 

 15-20 mm. long, short-pedicelled ; calyx-tube campanulate with short broad 

 unequal teeth, somewhat pubescent; pods glabrous, 2-4 cm. long, 6-8 mm. 

 broad. Common in copses. 



Vicia americana linearis (Nutt.) Wats. Leaflets linear, acute. In dry 

 ground, infrequent. 



213. LATHYRUS. 



Mostly smooth perennial herbaceous vines or erect herbs; leaves 

 pinnate, mostly with tendrils or tendrils much reduced or want- 

 ing; flowers in racemes or sometimes solitary; peduncles usually 

 equalling or exceeding the leaves and several-flowered; calyx- 

 teeth nearly equal or the upper ones somewhat shorter than the 

 lower; corolla rather larger than in Vicia; stamens diadelphous 

 or monadelphous below; style dorsally flattened near the top, 

 hairy on the inner side; ovules generally numerous; pod flat or 

 terete, 2-valved. 



Plants climbing by simple or 3-forked tendrils. L. pauciflorus. 

 Plants erect; tendrils wanting or much reduced. 



Corolla white; leaflets oblong or ovate. L. obovatus. 



Corolla purple; leaflets linear to obovate. L. bijugaius. 



Lathyrus pauciflorus Fernald. Glabrous throughout, 60-90 cm. high; 

 stems angled; leaflets 3-6 pairs, oblong-elliptic, thickish, prominently veined, 

 paler beneath, acute and cuspidate, rounded at base, 2-4 cm. long; stipules 

 about half as long as the adjacent leaflets; tendrils simple or branched; pe- 

 duncles exceeding the leaves, 3-S-flowered; flowers violet, about 2 cm. long; 

 calyx-teeth slightly pubescent, about as long as the tube; pods smooth, 4-6 

 cm. long. Warm slopes, infrequent. 



Lathyrus pauciflorus tenuior Piper. Leaflets linear or linear-lanceolate, 

 3-6 cm. long, otherwise as in the species. Less common than the species. 



Lathyrus obovatus (Torr.) White. Erect or decumbent, 12-25 cm. high; 

 leaflets 1-2 pairs, elliptic or ovate, obtuse, cuspidate, thinly pubescent and 

 paler beneath, 2-4 cm. long; stipules narrow, acuminate; tendrils none; 

 peduncles exceeding the leaves, 2-4-flowered; flowers stout-pedicelled, white 

 or ochroleucous, nearly 2 cm. long; calyx-teeth triangular-acute, shorter than 

 the tube. Waitsburg, Horner, and near Troy, Idaho. 



Lathyrus obovatus stipulaceus White. Stipule broadly ovate, obtuse, 

 one-third to one-half as large as the leaflets; flowers more numerous. Near 

 Spokane. 



Lathyrus bijugatus White. Erect, 10-15 cm. high, glabrous or sparsely 

 pubescent; stems not winged; leaflets 1-2 pairs, oblong or elliptic, acute, 

 cuspidate, about 2 cm. long; stipules sagittate, narrow, 5-10 mm. long; tendrils 

 none, but the rachis prolonged into a slender tip; peduncles shorter than the 

 leaves, 1-4-flowered; calyx-teeth triangular, acute, about as long as the tube; 

 corolla purple, 8-10 mm. long. On atony hillsides. 



Lathyrus bijugatus sandbergii White. Leaflets linear or linear-lanceolate, 

 4-6 cm. long. With the species on stony hillsides. 



