Astragalus ripleyi Barneby
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Authors
Rupert C. Barneby
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Authority
Barneby, Rupert C. 1964. Atlas of North American Astragalus. Mem. New York Bot. Gard. 13(1): 1-596.
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Family
Fabaceae
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Scientific Name
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Type
"4 miles south of Tres Piedras, Taos County, New Mexico ... 8 July, 1950, Ripley & Barneby No. 10307."—Holotypus, CAS! isotypi, COLO, GH, K, NY, POM, RM, RSA, WS, WTU!
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Description
Species Description - Tall and robust, strigulose nearly throughout with fine, straight, appressed hairs up to 0.35-0.5 mm. long, the herbage greenish-cinereous, the leaflets glabrous above; stems few, 1-6 from the subterranean root-crown, stout, erect and stiffly ascending, 4-7 dm. long, together forming graceful, broad-topped or inversely pyramidal clumps, buried at base for a space of 2-10 cm., simple, leafless and purplish below, branching upward from the first leafy node, the branches divaricate and incurved, the more vigorous ones producing spurs in most axils, often inserted between a peduncle and its subtending leaf; stipules 1-5 mm. long, the lowest papery-scarious, mostly broader than long, adnate to the vestigial petiole to form a bidentate sheath, decurrent around half to nearly the whole stem’s circumference, becoming fragile and irregularly ruptured, the upper ones herbaceous, very shortly adnate, with deltoid or triangular-acuminate, mostly deflexed blades; leaves 4—9 (11) cm. long, commonly divaricate and incurved, shortly petioled or the uppermost subsessile, with 13-17 (19) rather distant, opposite or scattered, linear or linear-elliptic, or (in some upper leaves) subfiliform, obtuse, rarely subacute or truncate, loosely involute leaflets (3) 9-25 (35) mm. long, the terminal one nearly always decurrent; peduncles arcuate-erect, (3.5) 6-12 (15) cm. long, mostly much longer than the leaf; racemes loosely (5) 15—45-flowered, the flowers early declined and secund, the axis (2) 4—16 cm. long in fruit; bracts scarious, ovate-acuminate or lanceolate, 1—2 mm. long; pedicels very slender, at first straight, widely ascending, 2.3-3.5 mm. long, in fruit arched downward or twisted at base around the raceme-axis and abruptly refracted, 3-7 mm. long; bracteoles 0; calyx 5.5-7.7 mm. long, thinly strigulose with black or sometimes a few white hairs, the oblique disc 1—1.4 mm. deep, the membranous, pallid, deeply campanulate or subcylindric tube 5—6.6 mm. long, 2.9—3.3 mm. in diameter, the deltoid or triangular-subulate teeth 0.5—1.1 mm. long; petals pale lemon-yellow, con- colorous; banner recurved through ± 35°, oblanceolate or rhombic-oblanceolate, (13) 14-17 mm. long, 4.5-6.3 mm. wide; wings (11) 12.5-14.2 mm. long, the claws 5.9—7.1 mm., the oblong-oblanceolate, obtuse, nearly straight blades 6.5 8.2 mm. long, 2.1—2.8 mm. wide; keel (9.5) 10—11.3 mm. long, the claws (5.5) 6-7 mm. long, the lunately half-obovate blades 4.5-5.5 mm. long, 2.2-2.6 mm. wide, incurved through 85-95° to the bluntly deltoid apex; anthers 0.6-0.8 mm. long; pod pendulous, stipitate, the slender, straight stipe 8-15 mm. long, the body linear-oblong, lanceolate, or narrowly elliptic in profile, straight or a trifle arched downward, (1.4) 2-3.3 cm. long, (3.5) 4-6 mm. in diameter, mostly cuneate at base and tapering from above the middle into a very acute, cuspidate apex, strongly compressed laterally and 2-sided, bicarinate by the salient, subfiliform sutures, the faces at first nearly flat becoming low-convex at maturity, the thinly fleshy, green or reddish, finely strigulose valves becoming papery, stramineous, reticulate; ovules 11-17; seeds yellowish-brown, rugulose-punctate, dull, 2.8-3.4 mm. long.
Distribution and Ecology - Dry plains and stony meadows, among sagebrush, with Chrysothamnus spp., or on sandy banks in juniper-piñon woodland, commonly in loamy clays overlying granitic bedrock, 7000-8250 feet, local but forming colonies, known only from the upper Rio Grande Valley in Taos County, New Mexico, and along the Conejos River in adjoining Conejos County, Colorado.—Map No. 23.—June and July.
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Discussion
The Ripley milk-vetch and the species following, A. Schmollae, are both local, strongly marked astragali, somewhat isolated taxonomically but closely related to one another. The obcompressed pod of A. Schmollae is very similar to that of A. lonchocarpus, and it is through the Schmoll milk-vetch that the relationship of A. Ripleyi to the genuine Lonchocarpi is most readily perceived. On purely technical grounds, and especially if the lateral compression of the pod were emphasized at the expense of other characters, it would be possible to refer A. Ripleyi to sect. Collini, even though the calyx lacks the basal pouch characteristic of that section. The pod alone, in form, texture, and compression, is quite like that of A. (Cusickiani) filipes, but this differs much in habit of growth and in the connate lower stipules.
A handsome, tall astragalus, A. Ripleyi is like no other species of its region and will be recognized without difficulty by the effuse branching of the stems above their simple fistular base, by the narrow leaflets, nodding, lemon-yellow flowers, and finally by the large, pendulous, long-stipitate, bladelike pods which are commonly tinged with red in the fresh state.
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Objects
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Distribution
New Mexico United States of America North America| Colorado United States of America North America|