Astragalus drummondii Douglas ex Hook.
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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
"First, I believe, gathered by Mr. Wright, very many years ago, in Hudson’s Bay (Herb, nostr.). Eagle and Red-Deer Hills of the Saskatchewan, Douglas."—Holotypus, Douglas in 1826, K! Paratypus (Wright, but certainly not strictly from Hudson Bay), K!
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Synonyms
Tragacantha drummondii (Douglas) Kuntze, Tium drummondii (Douglas ex Hook.) Rydb., Astragalus drummondii f. melanocalyx Gand.
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Description
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Species Description - Commonly coarse and leafy, with a woody taproot and knotty, pluricipital root-crown at or shortly below soil-level, villous-hirsute with filiform, minutely bulbous-based, spreading and ascending, the straight or sinuous hairs up to 1.1-1.8 (2) mm. long, the stems and lower leaf-surface pallidly gray-green beneath the ashen vesture, the leaflets bicolored, brighter green and glabrous or medially glabrescent above, the inflorescence more shortly and often more thinly pubescent than the rest; stems several or many, erect or ascending in clumps, (2.5) 3-5.5 dm. long, usually stout, angular-ribbed and fistular, at base naked, simple, subterranean for a space of 0—6 cm., branched or spurred at (1) 2—6 nodes preceding the first peduncle; stipules submembranous, early becoming papery-scarious, (2) 3-12 mm. long, the lowest of two sorts: a) decurrent around 1/3-2/3 the stem’s circumference and free, or b) fully amplexicaul and connate into a bidentate sheath, in either case fragile and often irregularly ruptured early in the season, the median and upper ones always free, deltoid- or lance-acuminate, with narrow, often caudately attenuate, spreading or deflexed blades; leaves 4-10 (13) cm. long, all but the lowest ones subsessile, with (13) 17-33 often scattered and irregularly inserted, oval-oblong, oblong-oblanceolate, or obovate, obtuse, truncate, or emarginate, flat or loosely folded leaflets 4-25 (33) mm. long; peduncles stout, erect, (4) 6-12 cm. long, longer or shorter than the leaf; racemes 14-30 (35)-flowered, loose or early becoming so, the flowers early nodding, the axis elongating, (3) 5-15 (22) cm. long in fruit; bracts membranous, pallid, lanceolate, 2-5 mm. long; pedicels at anthesis ascending or somewhat spreading, 1.5-2.5 (3) mm. long, in fruit usually arched through 90°, (2) 3-5 mm. long; bracteoles 0-2; calyx 7-12.5 mm. long, strigulose-villosulous with black, white, or mixed hairs, the oblique disc 0.9-1.5 (2) mm. deep, the membranous, pallid, deeply campanulate tube (4.7) 5.5-8 mm. long, (2.9) 3.5-5.1 mm. in diameter, commonly a little tumid but not or scarcely gibbous dorsally at base, the subulate teeth (1.7) 2-4.5 (5) mm. long; petals white or pale cream-colored, the keel tipped with dull lilac; banner recurved through about 45°, oblanceolate, rhombic-oblanceolate, or -elliptic, 18.5-26 mm. long, 7-10.5 mm. wide; wings 15-21 mm. long, the claws 7-9 mm, the oblong oblanceolate or -elhptic, straight or slightly incurved blades (8.7) 9-12 mm. long, 2.3-3.3 (3.8) mm. wide, commonly obliquely truncate and notched on the lower side just below the obtuse or subacute apex; keel 12-15 mm. long, the claws (6.5) 7-8.7 mm, the half-obovate blades 5.4-7 mm. long, 2.6-3.3 mm. wide, abruptly incurved through 90-105° to the deltoid, sometimes obscurely porrect apex; anthers (0.5) 0.55-0.75 (0.8) mm. long; pod pendulous, stipitate, the slender, straight stipe (5) 6-11 (14) mm. long, the body linear-oblong or -oblanceolate in profile, 1.7—3.2 cm. long, 3.5—5.5 mm. in diameter, usually bent downward from its junction with the stipe, thereafter straight or gently either incurved or decurved, cuneate at both ends or sometimes tapering basally into the stipe, obliquely cuspidate at apex, subtriquetrously compressed, keeled ventrally by the prominent, usually purplish-brown suture, the lateral faces high-convex, the dorsal face deeply and narrowly sulcate, the green, somewhat fleshy, glabrous valves becoming stiffly papery or almost leathery, stramineous, cross-reticulate, somewhat torulose when fully ripe, inflexed as a complete or nearly complete septum 0.6—1.5 mm. wide; ovules (14) 16-26 (30); seeds brown or soot-brown, sparsely pitted but somewhat lustrous, 2-3 mm. long.
Distribution and Ecology - Open hills and plains, in grassland, oak brush, sagebrush piñon-juniper woodland or rarely pine forest, in light dry or moderately moist and heavy alluvial soils, with no apparent rock preference, 2200-8600 feet, widespread, common, and often locally abundant at middle elevations on the east slope of the Rocky Mountains and the higher prairies, from southern Alberta south to the head of the Canadian River and upper Rio Grande in northeastern and northcentral New Mexico, extending east over the plains to southern Saskatchewan, western North Dakota, the Black Hills in South Dakota, and eastern Colorado; also west of the Continental Divide but there common only in western Montana, from the Blackfoot River and Clarks Fork south just into southeastern Idaho (Clark County); rare and occasional in the Yampa and Gunnison Valleys, Colorado; apparently isolated in central Utah (Utah, Beaver, and Sevier Counties).—Map. No. 58. May to August.
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Discussion
The Drummond milk-vetch is a handsome, sturdy plant with hollow, ribbed stems, shaggy as are the leaves, with long, often sinuous hairs, and abundant, nodding flowers, whitish with lilac keel-tip. The flowers give rise to long, pendulous pods elevated out of the calyx on a stipe as long or up to twice longer than the tube. When first formed the pod is green and lustrous, keeled ventrally by a thick, commonly brownish-purple suture; the valves turn straw-color in ripening, when they are often a little constricted between the seeds. As the only tall and erect astragalus with hirsute foliage in its range of dispersal, A. Drummondii is easily recognized and almost never misnamed. Apart from the dimorphic stipules, a feature very unusual in the genus, and some fluctuation in stature and flower-size, such as must be expected in any far-ranging species, the Drummond milk-vetch varies little. Forms with partly black-hairy inflorescence are most common, but others with all black (fma. melanocalyx) or all white hairs are not infrequent.
Douglas and Drummond seem to have collected A. Drummondii almost simultaneously, Drummond at Carlton House (K), Douglas in Alberta. The two collectors sailed together from Hudson Bay to England in the fall of 1827, and the name of the species remains to remind us of their friendship.
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Objects
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Distribution
Alberta Canada North America| Saskatchewan Canada North America| Montana United States of America North America| North Dakota United States of America North America| South Dakota United States of America North America| Wyoming United States of America North America| Idaho United States of America North America| Utah United States of America North America| Colorado United States of America North America| Nebraska United States of America North America| New Mexico United States of America North America|