General: Perennial; stems solitary or few, 15-60 cm long, vine- like and climbing by its well-developed tendrils, or sometimes erect and independent of support; herbage glabrous or nearly so, pale and somewhat glaucous; rhizomes slender.

Leaves: Alternate, pinnate, terminating in a simple or branched tendril; leaflets 6-10, broadly ovate to broadly elliptic, 1.6-4.5 cm long, 0.9-2.5 cm wide, generally 1.5-2.7 times as long as wide, glabrous, pale and somewhat glaucous below, margins entire; stipules herbaceous, the ascending lobe ovate or lance-acuminate, mostly 5-9 mm long; blades petiolate.

Flowers: Inflorescence an axillary raceme, few- to many-flowered; calyx campanulate, the margins of the teeth and sinuses sometimes ciliate, otherwise glabrous; corolla 12-16 mm long, mostly white, sometimes tinged with pale purple or purple-veined, or bluish to purple; style pubescent on inner side for about half of its length; flowers April- September.

Fruits: Legume, elliptic-oblanceolate, 3.5-5 cm long.

Ecology: Meadows, slopes, pine or spruce-aspen forests; 1700-2600 m (5500-8500 ft); Apache, Coconino, Gila, Navajo, Pima, and Yavapai counties; southwestern U.S.

Notes: Lathyrus lanszwertii is distinguished from L. laetivirens primarily by its narrower leaf shape, bristles instead of tendrils at the leaf tips, and slightly shorter calyx (5- 7 mm long).

Editor: Springer et al. 2008