Lathyrus lanszwertii

Herbs perennial, from rhizome, glabrous or sparsely pubescent. Stems angled, erect, sprawling, or climbing, basally branched 0–4 times, 1–8 dm. Leaves (0.5–)1–8 cm; tendrils mucro­nate to well developed; stipules linear to lanceolate, 5–25 × 1–6 mm, much smaller than leaflets; leaflets 2–10, scattered, blades lanceolate or linear, 20–70 × 2–20 mm, surfaces glabrous or sparsely pubescent. Inflorescences 2–6-flowered, 2–10 cm. Flowers 7–15 mm; calyx lobes unequal, lateral lobes deltate, shorter than tube; corolla white or blue-purple, banner erect, blade equal to claw, wings equal to keel; ovary glabrous. Legumes 25–45 × 6–10 mm.

Distribution

w North America.

Discussion

Varieties 5 (5 in the flora).

Selected References

None.

Lower Taxa

Lathyrus lanszwertii var. aridus, Lathyrus lanszwertii var. bijugatus, Lathyrus lanszwertii var. lanszwertii, Lathyrus lanszwertii var. leucanthus, Lathyrus lanszwertii var. pallescens

Key

1	Stems (2–)3–8 dm, usually climbing, sometimes sprawling or erect; tendrils well developed, usually branched.	> 2
2	Leaflets 8–10; corollas blue-purple; California northward to Washington, eastward to Colorado and Wyoming.	Lathyrus lanszwertii var. lanszwertii
2	Leaflets 6–8; corollas white; w Colorado, c Utah, Wyoming.	Lathyrus lanszwertii var. pallescens
1	Stems 1–3(–4) dm, usually erect (sometimes var. bijugatus sprawling or climbing); tendrils reduced to simple bristles less than 1 cm.	> 3
3	Leaflets 2–4; e Washington, adjacent Idaho, Montana, British Columbia.	Lathyrus lanszwertii var. bijugatus
3	Leaflets 4–8; California northward to sc Washington and eastward to New Mexico, Colorado, and Wyoming.	> 4
4	Flowers 7–10 mm; California, Nevada, Oregon, Washington.	Lathyrus lanszwertii var. aridus
4	Flowers 10–15 mm; Arizona, Colorado, New Mexico, Utah, Wyoming.	Lathyrus lanszwertii var. leucanthus