Astragalus Whitneyi var. Sonneanus
-
Title
Astragalus Whitneyi var. Sonneanus
-
Authors
Rupert C. Barneby
-
Scientific Name
Astragalus whitneyi var. sonneanus (Greene) Jeps.
-
Description
87d. Astragalus Whitneyi var. Sonneanus
Low, slender, the prostrate, weakly ascending, or loosely tufted stems 2-12 (17) cm. long; herbage loosely strigulose or villosulous with subappressed, spreading and incurved, or incurved-ascending, often sinuous hairs up to 0.3-0.65 mm. long, greenish-cinereous or sometimes canescent, the leaflets pubescent on both sides; leaves 1.5-4 cm. long, the (5) 11-17 leaflets 2-10 (12) mm. long, often rather crowded; racemes shortly 4-9 (11)-flowered, the axis 0.5-2 (2.5) cm. long in fruit; calyx 4.8-6 mm. long, the tube 3.5-4.3 mm. long, (2.2) 2.5-3.3 mm. in diameter, the teeth 1-1.7 mm. long, petals whitish or cream-colored, sometimes lilac-tinged; banner 9-12.8 mm. long, 6.5—8.8 mm. wide; wings (0.7-2 mm. shorter) 7.8-11 mm. long, the claws 3.1-5 mm., the blades (5) 5.4-8.9 mm. long, (2) 2.2-3.2 mm. wide; keel (± equaling the wings) 7.5-11.2 mm. long, the claws 3.5—5 mm., the blades 4.2—6.5 mm. long, 2.3—3 mm. wide; pod loosely and sparsely strigulose, the stipe 2.5-5.5 (6) mm. long, the body (1.5) 2-4 (5.5) cm. long, (0.8) 1-2.2 (or, when pressed, up to 2.6) cm. wide; ovules 21-27.— Collections: 34 (o); representative: J. W. Thompson 10,539 (NY, WS, WTU), 14,758 (NY, SMU, WS, WTU); Kruckeberg 2513 (CAS, ID, NY, WS); Pickett 1537 (WS, WTU); Cronquist 7348 (CAS, ID, NY, RSA), 7417 (NY, RSA); Maguire & Holmgren 26,774 (NY, RSA, UTC).
Open rocky crests and summits near timber line, descending to well-drained gravelly flats and hillsides in the timber belt, on volcanic or metamorphic bedrock, especially abundant on serpentine, locally plentiful in scattered stations in interior Washington, Oregon, and westcentral Idaho: Wenatchee, and east slope of the Cascade ranges in Chelan, Kittitas, and Yakima Counties; Blue and Wallowa Mountains of southeastern Washington and northeastern Oregon; mountains of central transmontane Oregon in southern Gilliam, Morrow, eastern Grant, southern Wheeler, and northern Crook Counties; Steens Mountains, Harney County; Valley County (near Cascade), Idaho.—Map No. 32.—June to August.
Astragalus Whitneyi var. Sonneanus (Greene) Jeps., Fl. Calif. 2: 347. 1936, based on A. Sonneanus (Charles Frederick Sonne, 1845—1913, active in the n. Sierra Nevada in late XXIX century) Greene, Pittonia 3: 186. 1897, a legitimate substitute for A. Hookerianus (T. & G.) Gray in Proc. Amer. Acad. 6: 215. 1864 (non D. Dietr., 1850), based on Phaca Hookeriana (William Jackson Hooker, 1785-1865) T. & G., Fl. N. Amer. 1: 693. 1840.— "Interior of Oregon, probably near the Rocky Mountains, Douglas."—Holotypus, lacking locality-data but probably collected in the Blue Mountains, Columbia or Garfield County, Washington, GH! isotypi, BM (dated "1835"), NY, OXF (dated "1830")!—Tragacantha Hookeriana (T. & G.) O. Kze., Rev. Gen. 945. 1891. Astragalus Whitneyi subsp. Hookerianus (T. & G.) Abrams, III. Fl. Pac. St. 2: 583. 1944.
Torrey and Gray’s dedication of the northern balloon milk-vetch to the revered Sir William Hooker is an indication of how remarkable the species must have appeared at the time of its discovery. It remains a striking plant, even though it has come to bear, through accidents of duplication and misinterpretation (implicit in the synonymy, but cf. further Barneby, 1950, p. 206), the epithet Sonneanus intended in the first place to apply to the Sierran var. lenophyllus. The brightly mottled pod was originally described as "nearly two inches long," but only exceptionally reaches a length of 5 cm., and fruits 2—4 cm. long are commonest. The variety is easily recognized by its short racemes of small flowers, slender, decumbent stems, and ovary and pod at least thinly strigulose. The herbage varies from ashen to green in hue, and the petals, described by one collector in the Wenatchee Mountains as ochroleucous, are, at least sometimes in central Oregon, tinged with dull purple. Like var. siskiyouensis the northern balloon milk-vetch is especially abundant on outcroppings of metamorphic or serpentine bedrock, although not confined to such formations.