LEGUMINOSAE (PULSE FAMILY) 527 



43. LATHYRUS [Tourn.j L. VETCHLING. EVERLASTING PEA 



Style dilated and flattish (not grooved) above, hairy along the inner side 

 (next the free stamen). Sheath of the filaments scarcely oblique at the apex. 

 Otherwise nearly as in Vicia. Our species perennial and mostly smooth plants. 

 (Adflvpos, a leguminous plant of Theophrastus.) 



Stipules broadly ovate, regularly halberd-shaped 1. Z. maritimus. 



Stipules semi-cordate, serni-sagiltate, or with unequal sides. 

 Flowers purple or purplish to pink or white. 

 Leaflets 4-12. 



Principal leaves with 4-8 leaflets ; flowers 2-8 2. Z. palustris. 



Principal leaves with 8-12 leaflets ; flowers 10-25 (rarely as few as 6) . 3. L. venosus. 

 Leaflets 2. 



Steins and petioles winged 5. L. latifolius. 



Stems and petioles slender and wingless 6. Z. tuberosus. 



Flowers yellow or yellowish. 



Leaflets 4-6 ; flowers yellowish-white 4. Z. ochroleucus. 



Leaflets 2 ; flowers bright yellow . . . 7. Z. pratensis. 



1. L. marftimus (L.) Bigel. (BEACH PEA.) Stout, trailing or climbing, 0.3- 

 1 m. high ; stipules nearly as large as the leaflets, the lower lobe larger and 

 usually coarsely toothed ; leaflets mostly 6-10, thick, ovate-oblong, 2-6 cm. long ; 

 peduncles a little shorter than the leaves, 6-10-flowered ; flowers large (1.8-2.5 

 cm. long), purple. Seashores from N. J. and Ore. to the Arctic Sea; also on 

 Oneida L., N. Y., and the Great Lakes. June-Sept. (Eurasia.) 



2. L. palustris L. Slender, glabrous, the usually winged stems 0.5-1 m. 

 high ; stipules obliquely lanceolate to ovate, sharp-pointed at both ends; leaflets 

 3-4 (rarely 5) pairs, mostly 3.5-7 cm. long, lanceolate to elliptic, rather firm ; 

 peduncles 3-5(rarely S~)-flowered; flowers purple, 1.6-2.5 cm. long. Banks of 

 rivers and lakes, Que. to Alaska, s. to Me., Vt., w. N. Y., and the Great L. 

 region. June-Aug. (Eurasia.) Var. piL6sus (Cham.) Ledeb. Lower surface 

 of leaves, peduncles, calyces, etc. , pubescent. (L. myrtifolius, var. macranthus 

 T. G. White.) Nfd. and e. Que. to e. Me. (E. Asia.) 



Var. linearifblius Ser. Stems winged, 2-7 cm. high ; leaflets 2-3 (rarely 4) 

 pairs, linear to lanceolate, firm; peduncles 2-5-flowered ; flowers 1.4-1.7 cm. 

 long. Meadows (often brackish), shores, and open woods, Nfd. to Alaska, s. to 

 R. I., w. N. Y., and Minn. 



Var. myrtifblius (Muhl.) Gray. Stems very slender, wingless, 0.3-1 m. high ; 

 stipules sometimes broader; leaflets 2-3 pairs, elliptical, thinner, mostly 2- 

 4 cm. long; peduncles 3-9-flowered ; flowers 1-1.6 cm. long. (L. myrtifolius 

 Muhl.) By lakes and streams, w. Que. to Man., s. to N. C. and Tenn. 



3. L. venbsus Muhl. Stout, climbing, usually somewhat downy ; stipules 

 very small and mostly slender ; leaflets 4-6 pairs, oblong-ovate, mostly obtuse, 

 about 5 cm. long; peduncles many-flowered; flowers 1.2-1.6 cm. long. Shady 

 banks, N. J. and Pa. to the Sask., and south w. May-July. 



4. L. ochroleucus Hook. Stem slender, 3-9 dm. high ; stipules semicordate, 

 half as large as the thin ovate leaflets; peduncles 7-10-flowered ; flowers 1.5-1.8 

 cm', long, yellowish-white. Hillsides, w. Que. to Sask., s. to N. J., Pa., Great 

 L. region, la., S. Dak., and Wyo. May-July. 



5. L. LATIF6LJUS L. (EVERLASTING or PERENNIAL PEA.) Tall perennial 

 with broadly winged stems ; leaves and stipules coriaceous and veiny ; petioles 

 mostly winged; the 2 elliptic to lanceolate leaflets 0.5-1 dm. long; peduncles 

 stiff, many-flowered; flowers showy, pink, purple, or white. Frequently 

 cultivated, and escaping to roadsides and thickets, Ct. to I). C. (Introd. 

 from Eu.) 



6. L. TUBER6sus L. Slender perennial ; the rootstocks bearing numerous 

 tubers ; stems glabrous ; leaves and stipules thin; petioles and tendrils filiform ; 

 the 2 oblong leaflets 2-3.5 cm. long ; peduncles filiform, 3-6-flowered ; the fra- 

 grant violet flowers about 1.5 cm. long. Fields and meadows, locally established 

 in Vt. and Ont. June-Aug. (Introd. from Eurasia.) 



7. L. PRATENSIS L. Low and straggling ; the 2 bright green leaflets narrowly 



