Astragalus lentiginosus var. floribundus

  • Title

    Astragalus lentiginosus var. floribundus

  • Author(s)

    Rupert C. Barneby

  • Scientific Name

    Astragalus lentiginosus var. floribundus A.Gray

  • Description

    289d. Astragalus lentiginosus var. floribundus

    Similar to var. salinus but often more robust, the glabrous or thinly strigulose stems prostrate or weakly ascending, (2) 2.5-5 dm. long, nearly always branched or spurred in the lower half, the herbage green, the leaflets usually glabrous on both sides but ciliate, sometimes thinly strigulose beneath, rarely so above; leaves 3-8 (11) cm. long, with 11-15 (19) obovate, obovate-cuneate, oblong-obovate, or oblanceolate, mostly retuse, rarely subacute, flat or (in some upper leaves) folded leaflets 5-15 mm. long; peduncles (7) cm. long; racemes at first dense, (11) 15-30 (37)-flowered, the axis more or less elongating, 1-4 (10) cm. long in fruit, the pods crowded into dense, subglobose or cylindric heads; calyx 4—5.6 (6) mm, long, the tube 3—4 mm. long, 1.9—2.5 mm. in diameter, the teeth 0.6—1.4 (2) mm. long; petals whitish, the keel- and sometimes the wing-tips faintly lilac- tinged; banner broadly to narrowly rhombic-obovate, 8.8—11 (11.6) mm. long, 4-5.6 (6.2) mm. wide; wings 8.2-10.2 mm., the blades 5-6.7 mm. long; keel 6.68 mm., the blades 3.5-4.5 mm. long; pod obliquely ovoid-acuminate or subglobose, greatiy inflated, (0.8) 1.2-2.1 cm. long, (6) 7-12 mm. in diameter, the strongly incurved or suberect, triangular-acuminate beak 3—7 mm. long, the papery, often faintly mottled, at length stramineous valves glabrous or thinly strigulose; ovules 15-21 (25)—Collections: 26 (ii); representative: Jones 2990 (GH, NY, POM, UC); Kennedy 2072 (GH, NA, POM, UC); Ripley & Barneby 5878 (CAS, NY, RSA); Watson 238 (GH, p.p.).

    Sagebrush valleys and brushy hillsides, in dry, commonly sandy, granitic or basaltic soils, 3800-5200 feet, locally plentiful and rather common along the east base of the Sierra Nevada from near Lake Tahoe north to Sierra Valley, in southern Washoe, Ormsby, and Lyon Counties, Nevada, and adjoining Sierra and Placer Counties, California, north in scattered stations to extreme southern Oregon, there passing into var. salinus; in Mono County passing south into var. ineptus.— Map No. 127.—May to July.

    Astragalus lentiginosus var. floribundus (abounding in flowers) Gray in Proc. Amer. Acad. 6: 524. 1865.—"Nevada, near Carson City, Dr. C. L. Anderson."—Holotypus, Anderson 157, collected in 1864, GH! isotypi, NY, US!—Cystium floribundum (Gray) Rydb. in N. Amer. Fl. 24: 411. 1929.

    Cystium ormsbyense (of Ormsby County, Nevada) Rydb. in N. Amer. Fl. 24 : 412. 1929. —"Type collected in Eagle Valley, Ormsby County, Nevada, 1902, Baker 1275 ... "—Holotypus (C. F. Baker), NY! isotypi F, ND, POM, UC!

    The var. floribundus reaches its characteristic development in the Sierra foothills and piedmont valleys between Sierra Valley and Lake Tahoe, where it is the only known representative of the freckled milk-vetch and easily recognized by its branching stems, by the length of the internodes relative to the short, often subsessile leaves, and by the racemes of relatively numerous flowers which give rise to compact globose or cylindric heads of bladdery fruits. Even in this small area, however, several minor variants occur, forms almost glabrous and others thinly pubescent throughout, forms with glabrous and others with strigulose pods (the differential feature of C. ormsbyense), and forms characterized by broad and flat or alternatively with narrow and folded leaflets. Northward the variety passes insensibly into var. salinus and southward (cf. Rose 50,159, CAS, NY, RSA, from Bridgeport, Mono County) into the montane var. ineptus, which differs ideally (and in the Sierra Nevada proper almost consistently) in its more loosely strigulose or villosulous vesture.

    In southeastern Harney County the late Prof. Peck collected in moist ground near Whitehorse Ranch a set of remarkable variants which deserve further study. One of these plants (Peck 27,277) is fairly typical var. salinus. Another (Peck 27,316) has rather firmer, ellipsoid pods and a raceme-axis reaching 6-11 cm. in length, and might be referred to var. floribundus although it is far from characteristic. A third (No. 27,321) has loosely racemose fruits of the var. salinus type and is somewhat intermediate between the other two except that the pod’s valves are strigulose. This puzzling group of plants (all at ORE) defies classification.