Leaves pinnately compound (leaflets diverge from a common axis, or rachis). Leaves generally even-divided, with 8, 10, or 12 leaflets, medium green. Leaflets oblong-lanceolate (much longer than wide, with the margins parallel to one another between the tip and base) to elliptical (symmmetrical oval), ~2-3.5 cm long, very short pedicelled (pedicels are the small stems connecting the base of a leaflet to the rachis or main leaf axis). From a distance, the leaflets look as though they are opposite in arrangement, but closer examination shows that each pair is slightly offset, or alternate, though the pairs are widely spaced from one another. The leaflets usually show a small acute peak (mucro) at the tips, otherwise having entire margins. The end of the rachis is commonly a trailing and twisted tendril, allowing the plant to grab things for support, helping give it a climbing/vining ability. The base of the compound leaf petiole (stalk attaching leaf to stem) has stipules (a pair of small leaf-like structures sometimes found where petioles meet stems). Inflorescence a raceme of 5-20 flowers arranged alternately along the raceme's rachis or central axis. The raceme is axillary, coming out from the junction of a compound leaf and the stem. The flower corollas may be white, pink, lavender, violet, purple, or blue, ~14-20 mm long atop a bell-shaped calyx ~12-15 mm long. Corollas have 5 petals, the upper 2 often marked with a darker network of veins. Flowers April through June. Fruit is a leguminous pod, ~4-6 cm long, glabrous or pubescent, containing 1 to several round or kidney-shaped peas, the pod breaking off from the plant and splitting to free the seeds. A perennial herbaceous vine usually over 40 cm tall that is common through much of California, especially in coastal counties in montane settings, in chaparral, oak woodland, coniferous or mixed forest under 1500 m. A few subspecies, and the species hybridizes with relatives, giving it some variability in the specifics of appearance.
Lathyrus vestitus (Fabaceae): Pacific pea, common Pacific pea, Bolander's pea, canyon sweet pea, Pacific peavine, wild pea
The development of this key was partially funded through the Geoscience Diversity Enhancement Program (Award #0703798) and through a course of re-assigned time provided by the CSULB Scholarly and Creative Activities Committee. Thanks also to the students in sections of biogeography, introductory physical geography, GDEP, and LSAMP for "test-driving" various editions of this key.