4. Lathyrus Myrtifòlius Muhl. Myrtle-Leaved Marsh Pea

Fig. 2627

Lathyrus myrtifolius Muhl.; Willd. Sp. Pl. 3: 1091. 1803. L. palustris var. myrtifolius A. Gray, Man. Ed. 2, 104. 1856. L. myrtifolius macranthus White, Bull Torr. Club 21: 448. 1894.

Perennial, usually quite glabrous sometimes pubescent; stems slender, angled, not winged, 1°-3° long, weak. Stipules obliquely ovate, or half-sagittate, 6"-12" long, often 4"-6" wide and toothed; leaflets 2-4 pairs, mostly 3 pairs, oval, oval-oblong or ovate, mucronate and acute or obtuse at the apex, narrowed at the base, 9"-2' long, 3"-7" wide, rather thin; tendrils branched, peduncles equalling the leaves, or shorter, 3-9-flowercd; flowers purple or purplish, similar to those of the preceding species; pod linear, glabrous, sessile, 1'-2 long, 3 1/2" wide or less.

In moist or wet grounds, New Brunswick to Manitoba, south to North Carolina and Tennessee. May-July.

4 Lathyrus Myrtif Lius Muhl Myrtle Leaved Marsh Pe 9694 Lathyrus Myrtif Lius Muhl Myrtle Leaved Marsh Pe 970

5. Lathyrus Decaphýllus Pursh. Prairie Vetchling

Fig. 2628

L. decaphyllus Pursh, Fl. Am. Sept. 471. 1814. Lathyrus polymorphus Nutt. Gen. 2: 96. 1818.

Perennial, erect or ascending, glabrous, or finely pubescent, 6'-18' high. Stems angled; stipules half-sagittate, acuminate, 4"-12" long, 1"-3" wide; leaves petioled; leaflets 3-7 pairs, obtuse or acute and mu-cronulate at the apex, narrowed at the base, thick, conspicuously reticulated, 1'-2 1/2' long, 3"-8" wide; stipules when present branched, but often wanting; peduncles usually shorter than the leaves; flowers purple, 1'-1 1/2' long, showy; pod linear, stipi-tate; seeds with a narrow stalk and short hilum.

Kansas (?), Idaho and Colorado to Arizona and New Mexico. March-July. Everlasting-pea.

6. Lathyrus Ornàtus Nutt. Showy Vetchling

Fig. 2629

L ornatus Nutt.; T. & G FL N. A. 1: 277. 1838.

Closely resembling the preceding species, but generally lower, often less than 1° high, glabrous or nearly so. Stipules lanceolate or linear, 2"-10" long; leaflets narrow, linear or linear-oblong, acute and mucronate, 4" - 12" long, \"-2." wide; tendrils commonly wanting; flowers purple, showy, 1'-1 1/2' long; pod linear, stipitate; seeds with a broad stalk and long hilum.

Prairies and plains, Oklahoma to Kansas and South Dakota, west to Colorado, Wyoming and Utah. May-June.

Lathyrus incànus (Rydb. & Smith) Rydb. differs in being villous-pubescent. It ranges from western Nebraska to Utah and Wyoming.

6 Lathyrus Orn Tus Nutt Showy Vetchling 9716 Lathyrus Orn Tus Nutt Showy Vetchling 972