Astragalus mollissimus Torr.
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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(2): 597-1188.
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Family
Fabaceae
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Scientific Name
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Type
"On the Platte."—Holotypus, collected by Dr. Edwin James, assistant surgeon U.S.A., on Long’s Expedition in 1820, NY! isotypus (a pod), GH!
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Description
Species Description - Low, often relatively robust and leafy, densely or quite loosely tufted, perennial but of only a few years’ duration, the taproot early becoming woody and the root-crown, in old plants, sometimes developing into a shortly forking caudex, the stems and foliage villous-tomentose (pilose) throughout, the leaves canescent, silvery, or rarely greenish, the vesture usually composed of two sorts of extremely fine hairs, one shorter, curly, entangled, the other longer, spreading-ascending, or rarely retrorse or forwardly appressed, straight or sinuous, spirally twisted, both (in most forms) turning rufous or tawny when dry; stems few or many, simple or nearly so, the outer ones prostrate and the inner ascending, often reduced to thick crowns invested with a thatch of imbricated stipules, when caulescent composed of several short internodes and sometimes up to 2 dm. long, but even then forming less than half the total height of the plant; stipules 3-17 mm. long, with broad, semiamplexicaul bases and blades varying from lanceolate to deltoid-acuminate, or drawn out into caudate-acuminate tips; leaves (3) 6-26 cm. long, all petioled (the petioles often thick, stiff, and subpersistent), with 11-35 suborbicular, ovate, obovate, or rhombic-elliptic, often thick-textured leaflets 3-45 mm. long, commonly diminishing upward along the rachis; peduncles (1.5) 3-25 cm. long, ascending at anthesis, nearly always prostrate or reclinate in fruit; racemes (5) 7-45-flowered, at first nearly always dense and short, the axis more or less elongating, (0.5) 1-17 cm. long in fruit; bracts membranous or early becoming so, lanceolate or lance-acuminate, 2.5—10 (12) mm. long; pedicels straight, ascending, at anthesis 0.5-1.5 mm. long, in fruit thickened and 1—3 mm. long, persistent; bracteoles commonly 0, in some vars. 0-2; calyx (7) 8—14 mm. long, pubescent like the herbage, the hairs white or exceptionally fuscous or black, the oblique, fleshy disc 1.1-2.3 mm. deep, the cylindric or deeply campanulate, submembranous, often purplish tube usually a trifle constricted upward and thus broadest below the middle, the dorsal side straight, the ventral side somewhat convex or even gibbous behind the pedicel, the lanceolate, subulate, or sometimes subulate-setaceous teeth (1.7) 2-5.5 mm. long, the whole becoming papery, ruptured, marcescent; petals pink-purple, dull pinkish-lavender, yellowish suffused with sordid lilac, or creamy- white drying stramineous, often tending to persist about the forming pod; banner gently recurved through about 30°, variable in outline but commonly broadly oblanceolate or spatulate, 12-24.5 mm. long, the long-cuneate claw expanded into an oval, ovate, rhombic-ovate, or rarely suborbicular, shallowly notched or subentire blade ?-½ as wide; wings as long or somewhat shorter, the blades narrowly oblong or lance-oblong, usually broadest just above the claw and thence often slightly incurved, obtuse or truncate at apex; keel shorter than the wings, the lunate or lunately half-obovate blades incurved through 80-100° to the rounded apex; anthers 0.5-0.9 mm. long; pod spreading or ascending, commonly humistrate, obliquely ovate, lance-elliptic, lunate, or linear-oblong in outline, 9-25 mm. long, 4-13 mm. in diameter, solid or ± turgid, sometimes decidedly inflated but never bladdery, rounded or (when broad) subtruncate or a trifle umbilicate at base, contracted distally into a short, conical or laterally flattened, deltoid beak, terete when narrow, obcompressed and shallowly sulcate along both sutures when broad, nearly straight to incurved through 90° or slightly more, the fleshy valves becoming stiffly papery, leathery, or subligneous, rugulose-reticulate, glabrous, strigose, or villous-tomentose, inflexed as a complete septum extending up to the base or into the apex of the beak; seeds almost round, olivaceous, purplish- or orange-brown, sometimes nearly black or purple-speckled, sparsely punctate to rugulose, dull. 2-2.8 mm. long.