Astragalus Woodruffi

Title

Astragalus Woodruffi

Authors

Rupert C. Barneby

Scientific Name

Astragalus woodruffii M.E.Jones

Description

119. Astragalus Woodruffi

Coarse, malodorous, sparsely leafy and broomlike, with a stout taproot and closely forking caudex buried in sand, densely strigulose-pilose with shorter, appressed and often flattened together with longer, narrowly ascending, straight or nearly straight hairs up to 1-1.25 (1.4) mm. long (these all basifixed or some of them attached laterally just above the lower end), the stems and herbage silvery- silky or greenish-cinereous, the leaflets (when present) pubescent on both sides; stems several or numerous, erect and ascending in well-furnished clumps, 3-5.5 (6.5) dm. long, simple and subterranean for a space of 6-10 cm., branched from the first emersed up to the first floriferous axil and the branches again branched or spurred (the spurs sometimes paired with a peduncle distally), the main branches stiffly and strictly ascending; stipules large and conspicuous, the lowest ones firmly papery, pallid, 1-2.5 cm. long, united behind the subobsolete petiole into a semi- or fully amplexicaul, many-nerved, obtusely bidentate sheath (when fully amplexicaul sometimes very briefly connate), the median and upper ones foliace- ous, ovate, obovate, or lanceolate, obtuse or acute, 0.5-1.5 (2.5) cm. long, broader than the contiguous pair of leaflets, embracing half or much less than half the stem’s circumference, pubescent dorsally; leaves 1.5-6.5 cm. long, shorter than or equaling the intemodes, with short or subobsolete petiole and 1-7 (9) distant, mostly irregularly inserted, linear, linear-oblong, or filiform, closely folded leaflets 2-17 mm. long, the terminal one elongate, all decurrent into the rachis; peduncles stout, strictly ascending or erect, (3.5) 5-16 cm. long, much surpassing the leaf; racemes (8) 10-45-flowered, rather dense in early anthesis, the flowers ascending, the axis early and often greatly elongating, 2-25 (30) cm. long in fruit; bracts herbaceous or firmly papery, lanceolate, 2.5-7 mm. long, silky dorsally; pedicels straight, narrowly ascending, at anthesis 1-2.7 mm., in fruit somewhat thickened, 1.5-5 mm. long; bracteoles commonly 2, minute or up to 3.5 mm. long, sometimes 0; calyx 7.2-10.9 mm. long, densely silky-pilosulous with white hairs, the subsymmetric disc 1—2 mm. deep, the deeply campanulate tube 4.2-6.6 mm. long, 3-4 mm. in diameter, the rather firm, lanceolate teeth (2.7) 3-6 mm. long, the whole becoming papery, prominently 5-nerved, marcescent unruptured; petals bright pink-purple, the banner with a pale, striate eye, the wing-tips paler or white; banner recurved through 35—45°, rhombic-obovate to broadly oblanceolate, shallowly notched, 11.7—18.3 mm. long, 6-9 mm. wide; wings 11—17.5 mm. long, the claws 4.9—7 mm., the narrowly oblong-elliptic or -oblanceolate, obtuse and erose or obscurely emarginate, slightly incurved blades 7-11.6 mm. long, 2.1-3 mm. wide; keel 9.4-14.3 mm. long, the claws 4.8-7.8 mm., the lunately half-obovate or -elliptic blades 5—7.4 mm. long, 2.5—3 mm. wide, gently incurved through 80—90° to the blunt apex; anthers 0.5—0.65 mm. long, pod erect, sessile, narrowly oblong in profile, straight or gently incurved, 1.4—2 cm. long, 3.5—4.8 mm. in diameter, rounded at base, cuspidate at apex, strongly compressed and 2-sided, bicarinate by the salient sutures, the thinly fleshy, densely strigulose valves becoming stramineous and stiffly papery, not inflexed, seeds narrowly oblong, green or purplish-green, ± pitted or wrinkled, 4.6—5.3 cm. long.—Collections: 10 (iii); representative: Maguire 18,207 (UTC), 18,156 (WTU); B. F. Harrison 11,173 (BRY, RSA, US); Barneby 13,138 (CAS, NY, RSA, US), 13,143 (CAS, NY, RSA).

Dunes and dunelike talus at the foot of sand bluffs or sandstone outcrops and escarpments, 4300-5300 feet, local but forming extensive colonies, known only from the east side of the Colorado Basin in Emery, Wayne and eastern Garfield Counties, Utah.—Map No. 49.—May to July.

Astragalus Woodruffi (Robert Woodruff, companion to Jones on trips into the deserts of central Utah) Jones, Rev. Astrag. 77, Pl. 4. 1923.—"On.the sandy foot of the San Rafael Swell."—Cotypi, collected by M. E. Jones on May 17 and 18, 1914, POM! isotypi, CAS, GH, NY, PH, RM, US, UTC, WS, WTU!—Homalobus Woodruffi (Jones) Rydb. in N. Amer. Fl. 24: 264. 1929.