This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
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.
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.
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.