Psorothamnus polydenius var. polydenius

  • Title

    Psorothamnus polydenius var. polydenius

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Psorothamnus polydenius (Torr. ex S.Watson) Rydb. var. polydenius

  • Description

    8a. Psorothamnus polydenius (Torrey) Rydberg var. polydenius

    (Plate VI)

    Leaves small, distant, the leaflets 3-6 pairs, obovate to suborbicular, 1-3 mm long; calyx either pilosulous equably from base upward (the hairs up to 0.3-0.6, rarely 0.7 mm long), or the tube externally glabrous and lustrous, only the teeth pilosulous; otherwise as in key; 2n = 10 II (Raven, Kyhos & Hill, 1965); 2n = 10 (Spellenberg, 1970). — Collections: 54 (o, sed pluries sterilem vidi).

    Sandy and gravelly, often alkaline flats and low hills, commonly associated with chenopods, sometimes on dunes, 880-2250 m (2930-7500 ft), forming colonies but seldom crowded into thickets, widespread through the basins of w. Nevada and along e. foothills of Sierra Nevada in adjoining California from Smoke Creek Desert and the Humboldt and Carson sinks s. to Owens Valley, and somewhat disjunctly to central Mohave Desert in San Bernardino County, in Nevada s. to s. Nye County and thence e., rarely, to the Beaver Dam Mountains in s.-w. Washington County, Utah. — Flowering mid-May to September, the fruits ripe from July onward. —Representative: California. Mono: Heckard & Bacigalupi 3511 (NY, SD); Balls & Lenz 21,865 (RSA, UC); Spellenberg 2108 (NY). Inyo: Duran 3316 (NY, UC); Raven 7001 (NY); L. S. Rose 42,188 (CAS, NY); Alexander & Kellogg 5304 (SD, UC). San Bernardino: Everett, Balls & Lenz 17,611 (NY, OKLA, RSA); Alexander & Kellogg 2311 (UC); Beal 597 (JEPS, WIS). Nevada. Washoe: Palmer 66 in 1876 (NY, UC, US); Munz 16,116 (UC); Griffiths & Hunter 491, 544 (NY). Humboldt: Train 3096 (NY, UC). Churchill: Kennedy 1709 (NY). Lyon: Hendrix 693 (UC). Mineral: O. C. Stewart 53 (UC). Esmeralda: Shockley 275 (NY, UC); Maguire & Holmgren 25,513 (NY, UC). Nye: Maguire & Holmgren 10,558 (NY, UC), 25,175 (NY); Reveal & Holmgren 1855 (NY). Lincoln: Hermanson 113 (UC). Utah. Washington: Nish 44 (NY).

    Psorothamnus polydenius (Torr. ex Wats.) Rydb., N. Amer. Fl. 24: 46. 1919 ("polyadenius"), based on Dalea polydenia (with many glands) Torr. ex Wats, in King, Geol. Exp. 40th Parallel, Botany 64, PI. IX. 1871. — "Border of Truckee Desert, Nevada; (W. W. Bailey) 4,200 feet altitude; July...First collected by Dr. Torrey near Carson Desert."— Lectotypus, Torrey 109bis, collected in 1865, GH! isotypus, NY (herb. Torr.)! paratypi, Bailey distrib. Wats. 251, GH, NY! — Parosela polydenia (Torr. ex Wats.) A. Hell., Catal. N. Amer. PI. ed. 2, 6. 1900 ("polyadenia").

    Dalea polydenia Torr. ex Wats. (?) var. subnuda (almost naked, of glabrate calyx- tube) Wats, in Brew. & Wats., Bot. Calif. 2: 441. 1880. — "Owen’s Valley, Dr. W. Matthews."— Holotypus, collected in 1877, GH! isotypus, NY! — Parosela polydenia var. subnuda (Wats.) Parish, Bot. Gaz. 55: 305. 1913. Psorothamnus subnudus (Wats.) Rydb., N. Amer. Fl. 24: 46. 1919.

    Typical Ps. polydenius varies in stature, the adult plant taking the form of a depressed dome of stiffly enlaced branchlets or, in favorable conditions, that of a definite bush or shrub with one or more softly woody trunks. The only notable variation in detail is that, often noticed, in vesture of the calyx, which may be either pubescent from base upward or externally glabrous below the pilosulous teeth. The form with glabrate, vernicose calyx- tube has been collected repeatedly in Owen’s Valley, California, near Independence, Laws, and Bishop in Inyo County, and near Benton in southern Mono County, and seems where present to exclude the pubescent form. This, however, occurs in the same region, near Deep Springs and Eureka Valley, as well as in immediately adjoining Esmeralda County, Nevada and on the central Mohave Desert. Exactly parallel variants are known in Ps. schottii and the quite local Ps. thompsonae, in both cases geographically localized but not displacing the commoner, more pubescent type. All are interpreted here as minor variants of no taxonomic consequence.