Herbs, perennial, 1–15 dm, green and glabrous or silvery-hairy; from superficial or shal­lowly buried root crown. Coty­ledons deciduous, petio­late. Stems erect or ascending, green or purplish, clustered, branched or unbranched. Leaves basal and/or cauline; stipules 2–12 mm; petiole 1–15 cm; leaflets (5 or)6–10, blades 10–60 × 4–10 mm, abaxial surface hairy, adaxial surface glabrous or hairy (but not strigose). Peduncles (1–)4–25(–30) cm; bracts usually deciduous, 3–4 mm. Racemes loose, 5–16(–25) cm; flowers whorled or not. Pedicels (1–)2–5(–7) mm. Flowers 5–15 mm; calyx 4–8 mm, bulge or spur 0–3 mm (may be variable on plant), abaxial lobe entire or 3-toothed, adaxial lobe entire or 2-toothed; corolla usually blue, sometimes purple, violet, pink, lilac, or white, banner patch yellowish to whitish, blue, brown, or absent, banner not much reflexed-recurved beyond midpoint, this less than 3 mm proximal to apex, banner glabrous or pubescent abax­ially, wings glabrous, lower keel margins glabrous, upper margins ciliate. Legumes (1–)2–3 cm, hairy or silky. Seeds (2 or)3–5(or 6), tan, brown, or red.

Distribution

w North America.

Discussion

Varieties 14 (14 in the flora).

Selected References

None.

Lower Taxa

Lupinus argenteus var. argentatus, Lupinus argenteus var. argenteus, Lupinus argenteus var. argophyllus, Lupinus argenteus var. fulvomaculatus, Lupinus argenteus var. heteranthus, Lupinus argenteus var. hillii, Lupinus argenteus var. holosericeus, Lupinus argenteus var. meionanthus, Lupinus argenteus var. moabensis, Lupinus argenteus var. montigenus, Lupinus argenteus var. palmeri, Lupinus argenteus var. parviflorus, Lupinus argenteus var. rubricaulis, Lupinus argenteus var. utahensis

Key

1	Calyx spur 1–3 mm.	> 2
2	Flowers in profile appearing open, spur pronounced.	Lupinus argenteus var. heteranthus
2	Flowers in profile appearing closed; spur less pronounced.	> 3
3	Petioles of proximal cauline leaves 1.5–3 cm.	Lupinus argenteus var. argophyllus
3	Petioles of proximal cauline leaves 3–12 cm.	Lupinus argenteus var. utahensis
1	Calyx bulge 0–1 mm, but not elongated into a spur.	> 4
4	Leaflets oblanceolate, flat, green, surfaces glabrous or adaxially pubescent; plants of cool, moist mountain meadows, stream banks, lakeshores.	> 5
5	Corollas pale blue with brown banner patch; pedicels 1–2.5 mm.	Lupinus argenteus var. fulvomaculatus
5	Corollas usually blue with yellow banner spot or none; pedicels usually 3–4 mm.	> 6
6	Stems unbranched and racemes sol­itary, terminal.	Lupinus argenteus var. rubricaulis
6	Stems branched, giving rise to several racemes.	> 7
7	Corolla wings (7.5–)8–10 mm.	Lupinus argenteus var. argentatus
7	Corolla wings 5–7.5 mm.	Lupinus argenteus var. parviflorus
4	Leaflets oblanceolate or elliptic-oblanceolate, narrow and often folded, surfaces gray or silver-pubescent; plants of dry open areas, foothills to mountains.	> 8
8	Stem hairs descending in backward direction or widely spreading.	Lupinus argenteus var. palmeri
8	Stem hairs forwardly appressed.	> 9
9	Flowers large, (7–)8–15 mm.	> 10
10	Basal and cauline leaves present at flowering.	Lupinus argenteus var. montigenus
10	Basal leaves absent at flowering.	> 11
11	Flowers (7–)8–12 mm.	Lupinus argenteus var. argenteus
11	Flowers 12–15 mm.	Lupinus argenteus var. moabensis
9	Flowers small, 5–7(–9) mm.	> 12
12	Banners densely pubescent.	> 40
40	Lupinus argenteus var. holosericeus.	> 12
12	Banner glabrous or thinly strigulose abaxially.	> 13
13	Wings 5.5–7 mm; banner usually thinly strigulose abaxially; Kai­bab Plateau, Arizona, Colorado, Nevada, New Mexico, Utah; elevation 2000–2800 m.	Lupinus argenteus var. hillii
13	Wings 5–6 mm; banner glabrous abaxially; Sierra Nevada, California, adjacent Nevada; elevation 1500–3500 m.	Lupinus argenteus var. meionanthus