Astragalus Purshii var. lectulus

Subacaulescent, forming small tufts or closely woven mats, similar at all points to var. tinctus except for the small size of all parts; leaves (1) 1.5-5 cm. long, with (3) 5—9 (11) obovate-cuneate or oblanceolate and obtuse, sometimes elliptic and subacute, often crowded leaflets 2-10 mm. long; racemes 1-3 (5)-flowered, often embedded in the leaves; calyx (5.6) 6.1-8.8 mm. long, the tube 4.5-7.2 mm. long, 2.2-3 mm. in diameter, the teeth 1.1-1.6 mm. long; petals pink or pale purple; banner 10.3-15 mm. long, 5.4-7 mm. wide; wings 10.2-13.6 mm. long, the claws 5.6-7.1 mm., the blades 5.4-7.8 mm. long, 1.6-2.3 mm. wide; keel 9.4-11.7 mm. long, the claws 5.8-7.2 mm., the blades 4-5.1 mm. long, 1.9-2.5 mm. wide; pod exactly that of var. Purshii or var. tinctus but smaller, 7.5-15 mm. long, 4-8 mm. in diameter, shaggy-villous with hairs up to 1.5-3.5 mm. long, ovules 24—32; seeds 1.4—2 mm. long.—Collections: 37 (iii); representative: Eastwood & Howell 8418 (CAS, GH); Heller 8318 (CAS, GH, PH); J. T. Howell 19,772 (CAS, RSA); Munz 5687 (POM); Parish 2997 (NY).

Dry open flats and benches in piñon-juniper or yellow pine forest, ascending on stony slopes and screes to crests above timber line, commonly on decomposed granites, 6000-11,000 feet, frequent and locally plentiful along the east slope and crest of the Sierra Nevada from Alpine south to Inyo County, California; west slope of the Sierra in Tuolumne County (±7800 feet); locally abundant about the east end of the San Bernardino Mountains, San Bernardino County.—Map No. 86.— May to August.

Astragalus Purshii var. lectulus (Wats.) Jones, Contrib. West. Bot. 10: 61, Pl. 6. 1902, based on A. lectulus (a little bed, from the softly matted foliage) Wats, in Proc. Amer. Acad. 22: 471. 1887.—"Common in sandy soil in Bear Valley, San Bernardino Mountains, at 6000 feet altitude (C. C. Parry, 1876; S. B. Parish, June, 1886); in the Sierra Nevada, near Sonora Pass, at 10,000 feet altitude (W. H. Brewer, July, 1863)."—Lectotypus, Parry in 1876, GH! paratypi, Brewer 1906, GH! Parish in 1886 (some numbered 1812), GH, ND, NY!—Xylophacos lectulus (Wats.) Rydb. in Bull. Torr. Club 52: 371. 1925.

Xylophacos argentinus (silvery) Rydb. in Bull. Torr. Club 52: 371. 1925.—"Type collected at Lone Pine, California, May 14, 1897, Jones..."—Holotypus, GH! isotypus, US!— A. Jonesii (Marcus Eugene Jones, 1852-1934) Abrams, I11. Fl. Pac. St. 2: 578, fig. 2810. 1944, a legitimate substitute; non A. argentinus (of Argentina) Manganaro, 1919.

The Sierran variety of the Pursh milk-vetch, var. lectulus, is defined more narrowly here than in the preliminary revision (Barneby, 1947, p. 509), a point already stressed in discussion of var. tinctus. The plants vary in stature from diminutive mats or small cushions, with flowers embedded in the crowded leaves, into looser and larger tufts simulating var. tinctus in habit of growth; the variation is apparently correlated with microhabitat and not simply with elevation. The dwarfest phase, characteristic of populations found along the Sierra crest, descends in arid gravelly places to the low limit of tolerance at about 6000 feet in the foothills, and it recurs in the San Bernardino Mountains on exposed gravelly knolls in Bear Valley and around Baldwin Lake. A looser phase, of which X. argentinus provides an extreme example, is a relatively uncommon plant of the foothills in Inyo and Mono Counties at 6000-7000 feet; it is found either in shelter of sagebrush or in relatively rich and moist soils.

The flowers of var. lectulus vary from pink-purple to pale flesh-pink. In the latter case the petals tend to turn yellowish on drying but are never ochroleucous (as described for X. argentinus or A. Jonesii by Rydberg and Abrams) in the fresh state.