Astragalus crassicarpus
Cat. Pl. Upper Louisiana, no. 6. 1813.
Plants (5–)10–50(–60) cm, pubescent; from subterranean or superficial, woody caudex or root-crown, caudex determinate, shortly forking (except var. berlandieri). Stems ascending or decumbent, 1–9 cm underground, sparsely strigulose. Leaves (2–)3.5–18 cm; stipules distinct, 3–10 mm, submembranous, glabrous abaxially; petiolate or subsessile; leaflets (11–)15–33, blades oblanceolate, oblong-oblanceolate, obovate, suborbiculate, or broadly oval to linear-elliptic, (2–)3–24 mm, apex obtuse, acute, subacute, or truncate-emarginate, sometimes apiculate, surfaces pubescent abaxially, glabrous or glabrescent adaxially. Peduncles ascending to spreading, (1.5–)2–16 cm. Racemes (5–)6–25(–35)-flowered, flowers ascending or slightly arched; axis 1–7(–14) cm in fruit; bracts 2.5–7.5 mm; bracteoles 0–2. Pedicels 2–7.5 mm. Flowers (16–)16.5–25(–27) mm; calyx usually broadly or deeply campanulate or cylindro-campanulate, rarely cylindric, (6.6–)7.7–14 mm, densely strigulose, pilosulous, ascending-pilose, or villosulous-tomentulose, tube (5.2–)5.6–9.7 mm, lobes subulate or triangular-subulate, (1.3–)1.7–4.2(–5.8) mm; corolla pink-purple, red-purple, white, whitish (faintly lilac-tinged), lilac, ochroleucous, or suffused pinkish lilac; keel (10.7–)12–20.7 mm. Legumes green, often red-mottled or suffused with red on adaxial surface, becoming brown or blackish, straight, globose, subglobose, broadly and plumply oblong-ellipsoid, oblong-ovoid, or oblong-obovoid, ± obcompressed, 15–40 × 12–27 mm, fleshy becoming alveolate-spongy or pithy, wrinkled on drying, mesocarp at least 1.2 mm thick, glabrous. Seeds 34–77.
Distribution
w, c North America.
Discussion
Varieties 5 (5 in the flora).
The fleshy fruits of Astragalus crassicarpus are burnished with red or purple and resemble small plums prior to maturity. Early travelers valued the immature fruits as a summer vegetable. Ultimately, the surface collapses as the mesocarp dries. The fruits are frequently broader than long (S. L. Welsh 1960).
Selected References
None.
Lower Taxa
Key
| 1 | Calyces usually densely villosulous-tomentulose, hairs entangled, cream or brownish; corollas usually ochroleucous or suffused with pinkish lilac; racemes 13–25-flowered; peduncles 6–16 cm; stems usually ascending, rarely decumbent, (2.5–)3.5–6 cm; legumes 25–32 mm. | Astragalus crassicarpus var. trichocalyx |
| 1 | Calyces strigulose, pilosulous, or ascending-pilose, hairs mixed black and white or all black; corollas pink- or red-purple, lilac, or whitish; racemes (5–)6–23(–35)-flowered; peduncles (1.5–)2–9(–11) cm; stems usually decumbent (sometimes ascending in var. cavus), 5–40(–50) cm; legumes 15–40 mm. | > 2 |
| 2 | Stems arising singly or few from subterranean caudex, branches creeping, forming loose mats or colonial; seeds 34–50; Balcones Escarpment and vicinity, c, e Texas. | Astragalus crassicarpus var. berlandieri |
| 2 | Stems clustered from root-crown or superficial or subterranean caudex, not forming mats or colonial, caudex determinate; seeds 38–68; Alberta to Arizona eastward to Oklahoma panhandle. | > 3 |
| 3 | Corollas pink- or red-purple; herbage bright green (under vestiture). | Astragalus crassicarpus var. crassicarpus |
| 3 | Corollas white or whitish and faintly lilac-tinged; herbage pallid green or yellowish. | > 4 |
| 4 | Legumes globose or plumply ovoid-oblong or obovoid-oblong; Alberta southward to Oklahoma panhandle and adjacent New Mexico. | Astragalus crassicarpus var. paysonii |
| 4 | Legumes broadly and plumply oblong-ovoid, oblong-obovoid, or subglobose; ec Arizona, c New Mexico. | Astragalus crassicarpus var. cavus |