Native Plants
Plant Database
Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.
Astragalus atratus var. owyheensis
Astragalus atratus S. Watson var. owyheensis (A. Nelson & J.F. Macbr.) M.E. Jones
Owyhee Milkvetch
Fabaceae (Pea family)
Synonym(s): Astragalus owyheensis
USDA Symbol: ASATO
USDA Native Status: L48 (N)
"Variable in stature but extremely slender and delicate in all its parts, strigulose nearly throughout with straight, appressed and subappressed hairs up to 0.3-0.6 mm. long, the herbage greenish-cinereous, the leaflets glabrous or nearly so above; stems numerous, slender, radiating and weakly ascending (often supported by sagebrush), mostly short, 1-15 (20) cm. long, numerous and closely tufted, greatly surpassed by the inflorescences." (bibref: 1813).
"The Owyhee milk-vetch is one of the most delicately fashioned of all astragali. Its many very slender stems, its threadlike peduncles and petioles (the latter beset with tiny, scattered leaflets), and its airy, remotely flowered racemes of small, whitish flowers succeeded by narrowly ellipsoid pods pendulous from capillary pedicels all contribute to a characteristic elegance of habit. According to Jones (1923, l.c.) the plants of i>A. a. var. owyheensis can become three feet in diameter in grassy meadows; in the more usual habitat of stony flats and dry hillsides among sagebrush, the loosely woven mats or semiprostrate tufts are rarely half as large. The peduncles and racemes together are commonly longer than the proper stems." (bibref: 1813).
From the Image Gallery
No images of this plant
Plant Characteristics
Duration: PerennialHabit: Herb
Leaf Arrangement: Alternate
Fruit Type: Legume
Size Notes: "Stems numerous, slender, radiating and weakly ascending (often supported by sagebrush), mostly short, 1-15 (20) cm. long." (bibref: 1813).
Leaf: "Stipules 1-3.5 mm. long, dimorphic, the lowest ones approximate and often loosely imbricated, mostly ovate or broadly lanceolate and obtuse, papery-scarious, conspicuously adnate to the petiole-base, decurrent around half to the whole stem's circumference, the median and upper ones narrower and shorter, with triangular-lanceolate, subherbaceous blades; leaves (2) 4-14 cm. long, with slender petiole and 7-11 (13) remote, often scattered, linear-elliptic, involute or conduplicate leaflets 1.5-7 (10) mm. long, those of the upper leaves reduced in size, the terminal one continuous with the very slender or filiform rachis." (bibref: 1813).
Flower: "Peduncles subfiliform, (1.5) 3.5-12.5 cm. long, a little shorter to much longer than the leaf; racemes remotely (3) 5-12-flowered, the flowers nodding, the axis elongating, (2) 5-17 cm. long in fruit; bracts membranous, ovate or lanceolate, (0.8) 1-2.5 mm. long; pedicels very slender or filiform, (1.5) 2-4.7 mm. long at anthesis, in fruit straight and ascending at a wide angle or spreading, or more of less contorted, or abruptly refracted, 2.5-6.5 mm. long; bracteoles 0, if present minute; calyx 3-5.8 mm. long, strigulose with black, white, or mixed black and white hairs, the subsymmetric disc (0.5) 0.7 1.1 (1.5) mm. deep, the campanulate tube 2.3-4 mm. long, 1.7-2.7 mm. in diameter, the subulate teeth 0.7-2.1 mm. long; petals whitish, faintly lavender-tinged; banner 6.3-9.9 mm. long, 4-6.4 mm. wide, the shortly cuneate claw expanded into an oblong or ovate-oblong, deeply retuse blade 4-8.6 mm. wide, this pinched in at the middle in the form of two pocket-like folds and thus often appearing fiddle-shaped; wings (0.8-1.9mm. longer) 7.4-10.5 mm. long, the claws 2.8-4 mm., the obliquely obovate or half-obovate blades 5.2-7.2 mm. long, 2.2-3.6 mm. wide just below the rounded, erose, or shallowly emarginate apex; keel 5.9-7.7 mm. long, the claws 2.9-4 mm., the obliquely half-obovate or triangular blades 3.5-4.2 mm. long, 1.9-2.4 mm. wide, abruptly incurved through 95-120 degrees to the rather sharply deltoid, sometimes obscurely porrect apex; anthers 0.4-0.65 (0.8) mm. long." (bibref: 1813).
Fruit: "Pod stipitate, the stipe concealed by the marcescent calyx, 1-2 mm. long, the body narrowly elliptic-oblanceolate in profile, 1.4-2 cm. long, 3-4 mm. in diameter, tapering at base into the stipe, more or less abruptly cuneate at apex, gently decurved, or straight but the thick, salient ventral suture even then more convex than the dorsal one and the tip declined, variably compressed, uni- or bilocular, the slightly or scarcely fleshy, green, purplish, or mottled valves thinly papery, faintly reticulate, strigulose, not inflexed; ovules 10-17; seeds (little known) black, pitted or rugulose, about 2-2.5 mm. long." (bibref: 1813).
Bloom Information
Bloom Color: White , Purple , VioletBloom Time: May , Jun , Jul
Bloom Notes: "Petals whitish, faintly lavender-tinged." (bibref: 1813).
Distribution
USA: ID , NV , ORNative Distribution: "Local but plentiful in scattered stations, from the headwaters of the Powder and Burnt Rivers in Baker and northern Malheur Counties, Oregon, to adjoining Washington County, Idaho; also along the Bruneau River in Owyhee County, Idaho, south and east to southern Twin Falls County and the headwaters of the Humboldt River in northern Elko County, Nevada." (bibref: 1813).
Native Habitat: "Dry hillsides and gravelly flats, on basalt, usually taking shelter under and entangled in low sagebrush, 3500-6000 feet." (bibref: 1813).
Bibliography
Bibref 1813 - Atlas of North American Astragalus (1964) Barneby, Rupert C.Search More Titles in Bibliography
Additional resources
USDA: Find Astragalus atratus var. owyheensis in USDA PlantsFNA: Find Astragalus atratus var. owyheensis in the Flora of North America (if available)
Google: Search Google for Astragalus atratus var. owyheensis
Metadata
Record Modified: 2020-12-07Research By: Joseph A. Marcus