Astragalus convallarius

Plants clump-forming, slender, wiry, (10–)20–50(–70) cm, strigulose, hairs basifixed; from deep, subterranean caudex. Stems erect or ascending, 1–9(–17) cm underground, strigulose. Leaves sparse or nearly bladeless and rushlike, 2–11 cm; stipules connate-sheathing and papery-scarious at proximal nodes, mostly distinct and herbaceous at distal nodes, (1–)2–7 mm; leaflets 3–13 or distal leaves reduced to rachis (phyllodia), blades linear, linear-filiform, linear-elliptic, or elliptic, 5–30 × 0.5–4 mm, apex acute, surfaces strigulose; terminal leaflet sometimes decur­rent and not jointed to rachis. Peduncles incurved-ascending, 1–14 cm. Racemes 3–25-flowered, flowers ascending to declined; axis 2–20(–23) cm in fruit; bracts 0.5–2.3 mm; bracteoles 0–2. Pedicels 1–8 mm. Flowers (6.6–)7.6–11.2 mm; calyx 4–6.3 mm, black-strigose and/or white-strigose, tube 3.4–5.4 mm, lobes triangular-subulate, 0.5–1.4 mm; corolla ochroleucous, sometimes tinged or veined with purple or pink; banner abruptly recurved through 90°; keel (6.2–)6.5–9.4 mm, apex broadly triangular. Legumes pendulous to spreading, green, purple, or mottled, becoming stramineous, straight, linear, narrowly oblong, or oblanceoloid, lat­erally compressed, bicarinate, 13–50(–53) × 2.3–5 mm, papery, strigose; sessile. Seeds 11–26.

Distribution

w United States.

Discussion

Varieties 4 (4 in the flora).

Astragalus convallarius is known to contain nitro­toxins that are poisonous to livestock, especially sheep (L. F. James and S. L. Welsh 1992).

Selected References

None.

Lower Taxa

Astragalus convallarius var. convallarius, Astragalus convallarius var. finitimus, Astragalus convallarius var. margaretiae, Astragalus convallarius var. scopulorum

Key

1	Legumes linear to narrowly oblong, gradually or abruptly contracted to ± symmetric apex; Montana south to Colorado west to Nevada and Arizona.	> 2
2	Legumes linear or linear-lanceoloid, 25–50(–53) × 2.5–3.3(–4.2) mm, lengths 8–18 times widths; Montana south to Colorado west to Nevada and Arizona.	Astragalus convallarius var. convallarius
2	Legumes linear to narrowly oblong, 13–24(–30) × 3.4–4(–4.5) mm, lengths 4–8(–10) times widths; extreme sw Utah and adjoining Nevada.	Astragalus convallarius var. finitimus
1	Legumes oblanceoloid, tapering downward into calyx from obliquely triangular apex; w Colorado or wc Nevada.	> 3
3	Leaflets 7–11 throughout; wc Nevada.	Astragalus convallarius var. margaretiae
3	Leaflets 3–13 proximally, some distal leaves reduced to naked rachis or with at most 1 pair of filiform leaflets; w Colorado.	Astragalus convallarius var. scopulorum