Astragalus lentiginosus var. chartaceus

M. E. Jones

Proc. Calif. Acad. Sci., ser. 2, 5: 673. 1895.

Common names: Cobweb milkvetch
Endemic
Basionym: Astragalus araneosus E. Sheldon Minnesota Bot. Stud. 1: 170. 1894
Synonyms: A. lentiginosus var. araneosus (E. Sheldon) Barneby
Treatment appears in FNA Volume 11.

Plants perennial, 10–35 cm. Stems diffuse and incurved-ascending, often red-tinged. Leaves (2.5–)4–11 cm; leaflets (9 or)11–23, blades elliptic-oblanceolate, broadly oblong-oblanceolate, or obovate, (3–)5–17(–20) mm, apex obtuse or emar­ginate. Pedun­cles (1–)2.5–6(–7.5) cm. Racemes (5–)10–20-flowered, flowering from middle and distally, short and compact in fruit; axis (0.5–)1.5–4(–5.5) cm in fruit. Flowers (12.5–)15–18.2 mm; calyx (6.2–)7.5–10.5 mm, tube (4.6–)5.2–6.7 mm, lobes 1.4–3.8 mm; corolla bright pink-purple with pale, striate eye. Legumes green, often red-mottled, becoming stramineous, usu­ally strongly incurved, ovoid, lanceoloid-ovoid, or ovoid-acuminate, moderately inflated, 15–30(–40) × (7–)9–15 mm, biloc­ular, stiffly papery or almost leathery, usually glabrous, rarely puberulent; beak well-defined, triangular or del­toid, 6–15 mm, unilocular. Seeds 24–34(–38).


Phenology: Flowering May–Jul.
Habitat: Sagebrush, pinyon-juniper, and mixed desert shrub communities, on alluvial silt, igne­ous gravel.
Elevation: 1400–2200 m.

Discussion

Variety chartaceus is widespread from central to western Utah into northeastern and central Nevada, there intergrading with vars. fremontii, kennedyi, and toyabensis. S. L. Welsh (2007) discussed the problems of including this variety in an expanded var. diphysus and its complex relationships to other varieties.

Selected References

None.

Lower Taxa

None.
Stanley L. Welsh +
M. E. Jones +
Astragalus araneosus +
Cobweb milkvetch +
Nev. +  and Utah. +
1400–2200 m. +
Sagebrush, pinyon-juniper, and mixed desert shrub communities, on alluvial silt, igneous gravel. +
Flowering May–Jul. +
Proc. Calif. Acad. Sci., ser. +
A. lentiginosus var. araneosus +
Astragalus lentiginosus var. chartaceus +
Astragalus lentiginosus +
variety +