LEGUMINOSAE (PEA FAMILY) 301 



1. Vicia americana Muhl. Willd. Sp. PI. 3: 1906. 1803. Glabrous; stems 

 climbing or scrambling, 5-10 dm. long: leaflets 10-14, elliptical-lanceolate or 

 ovate-oblong, obtuse or retuse, mucronate, 20-30 mm. long; stipules deeply 

 toothed: peduncles shorter than the leaves, 4-8-flowered; flowers purplish- 

 blue, 18-20 mm. long: pods linear-oblong, reticulated. Frequent; across the 

 continent especially northward. 



la. Vicia americana oregana (Nutt.) A. Nels. Somewhat pubescent; stems 

 weak: leaves mostly lance-oblong, usually some of them truncate or serrate 

 at apex. (V. oregana Nutt. and V. truncata Nutt. T. & G. Fl. 270.) 



2. Vicia linearis (Nutt.) Greene, Fl. Francis. 3. 1891. Nearly glabrous; 



ims decumbent or scrambling: leaflets 8-14, linear, often obtuse, apiculate; 



ndrils short, simple or bifid; stipules laciniate-toothed or incised below: pe- 

 duncles 3-4-flowered, shorter than the leaves; flowers large (18-25 mm. long), 

 pale purple: style nearly filiform, villous around the summit. Very common 

 throughout our range and westward. 



2a. Vicia linearis caespitosa A. Nels. A reduced form, the stems branched 

 and matted. With the species. 



3. Vicia producta Rydb. Bull. Torr. Club 28: 500. 1901. Sparsely pubes- 

 cent perennial; stems slender, branched, angled and leafy: leaflets 6-10, ob- 

 long to linear: peduncles 2-3-flowered, distinctly produced beyond the small 

 lateral flowers: calyx-tube about 2 mm. long, exceeding its lance-subulate 

 teeth: corolla ochroleucous with purplish tip. Southern Colorado. 



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18. LATHYRUS L. PEA OR VETCH 



Our species are perennial and mostly smooth plants, the rachis of the 

 ,ves in some not produced into a tendril. Style flattish, dilated (not grooved) 

 ove, hairy along the inner side (next the free stamen). Sheath of the fila- 

 ments scarcely oblique at the apex. Otherwise nearly as in Vicia. 



Flowers purple. 



Leaves not tendril-bearing. 

 Leaves linear. 



Glabrous 1. L. ornatus. 



Villous-canescent . . . . . . . . . 2. L. incanus. 



Leaves lance-oblong 3. L. decaphyllus. 



Leaves tendril-bearing . . . . . . . . . 4. L. arizonicus. 



Flowers white or yellowish. 

 Leaves linear to oblong. 



Stipules semisagittate . ........ 5. L. leucanthus. 



Stipules foliaceous 6. L. ochroleucus. 



Leaves ovate, conspicuously veiny . . . . . . . 7. L. utahensis. 



1. Lathyrus ornatus Nutt. T. & G. Fl. N. A. 1: 277. 1838. Erect, glabrous, 

 often glaucous; stem 1-2 dm. high, sometimes branched, quadrangular: leaf- 

 lets 3-4 pairs, lanceolate-linear, acute, mucronate, rigid and strongly veined, 

 tendrils scarcely any; stipules linear-lanceolate and slender, semisagittate, 

 entire: peduncles about 4-flowered, longer than the leaves; flowers large, 

 purple, 2-3 cm. long, very showy: calyx-teeth subulate, slightly unequal, 

 rather shorter than the tube: pod smooth, flat, acuminate at each end. Plains 

 at the eastern base of the Rocky Mountains. 



2. Lathyrus incanus Rydb. Size and habit of the preceding, densely 

 villous-canescent throughout, otherwise quite "similar. Sandy banks and 

 washes; Wyoming and Nebraska. 



3. Lathyrus decaphyllus Pursh, Fl. Am. Sept. 471. 1814. Mostly glabrous; 

 stem erect, slightly woody at the base, much branched, a little quadrangular, 

 about 3 dm. high: leaflets 2-5 pairs, elliptical-lanceolate, somewhat glaucous, 

 rigid, strongly veined; stipules lanceolate, subfalcate, semisagittate at base: 

 peduncles 3-5-flowered, rather shorter than the leaves; flowers large, purple: 

 segments of the calyx broadly or narrowly subulate, somewhat unequal, 

 shorter than the tube: pod large, glabrous. L. polymorphus. Throughout 

 the Rocky Mountains of the United States. 



4. Lathyrus arizonicus Brit. Trans. N. Y. Acad. Sci. 8: 65. 1889. Per- 

 ennial, glabrous or somewhat pubescent; stem often winged: leaflets 4-8, 



