Astragalus bisulcatus var. Haydenianus

  • Title

    Astragalus bisulcatus var. Haydenianus

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Astragalus bisulcatus var. haydenianus (A.Gray) Barneby

  • Description

    108b. Astragalus bisulcatus var. Haydenianus

    Usually robust, the stems commonly decumbent and radiating, sometimes erect and ascending in clumps, (1.5) 3-5 (7) dm. long; leaflets (13) 21-35, 0.5—2.7 cm. long; racemes mostly 35—80-flowered, becoming narrowly cylindrical, the fruiting axis (4) 5.5-25 cm. long; bracts (2.5) 3-5 mm. long; calyx-tube pallid, 3.1-4 mm. long, 2.3-2.7 mm. in diameter, the subulate teeth 1-2.7 mm. long; petals white or whitish; banner 8-11 mm. long, (3) 3.3-5 mm. wide; wings 7.1-10.2 mm. long, the claws 3.3-4.7 mm., the blades (4.6) 5-6.7 mm. long, 1.4—2.1 mm. wide; keel 6.7—9.6 mm. long, 0.5—2.5 mm. shorter than the banner, the claws 3—4.2 mm., the blades (3.8) 4.3—6 mm. long, (2) 2.2—2.6 mm. wide; anthers 0.45—0.6 mm. long; stipe of the pod 1.4—3 mm. long, the body ellipsoid or oblong-ellipsoid, (5) 6.5—9.5 mm. long, 2-4 mm. in diameter, the valves strigulose with white or black hairs, transversely rugulose-reticulate; ovules 5—8.— Collections: 35 (iv); representative: W. A. Weber 4741 (CAS, OKLA., SMU, TEX, WS); Bethel, Willey & Clokey 4194 (CAS, NY, WS); M. & G. Ownbey 3024 (CAS, NY, RSA, SMU, WS); A. Nelson 3786 (NY); Ripley & Barneby 5320 (CAS, NY, RSA).

    Sagebrush plains, dry hillsides, and gullied bluffs, sometimes in great abundance on over-grazed pastures, in stiff alkaline clay, black shale, or sandy clay overlying sandstone, 6500—8750 feet, locally common on the west slope of the Rocky Mountains in Colorado, about the headwaters of the Yampa, Grand, and thence south to the middle Gunnison and upper San Juan Rivers, extending north along Vermillion Creek just into southern Sweetwater County, Wyoming, west into the Uinta Basin and foothills of the La Sal Mountains in extreme eastern Utah, and south and southwest to the upper Little Colorado in northwestern Apache County, Arizona, and McKinley County, New Mexico, and to the Rio Grande drainage at the head of Rio Puerco in Sandoval County.—Map No. 45—May to July.

    Astragalus bisulcatus var. Haydenianus (Gray), comb. nov., based on A. Haydenianus (Ferdinand Vandeveer Hayden, 1829-1887, leader of the Hayden Survey of the Rocky Mountains, "one of the most indefatigable and distinguished explorers of the region") Gray ex Brand. in Bull. U. S. Geol. Surv. 2s: 235. 1876.—‘"South-western Colorado, between Parrott City and the Mancos, 8000 feet."—Holotypus, Brandegee 1285, collected (at "7000 ft.") in the summer of 1875, GH! isotypi, K, US!—Tragacantha Haydeniana (Gray) O. Kze., Rev. Gen. 945. 1891. A. bisulcatus var. Haydenianus (Gray) Jones in Zoë 2: 240. 1891, nom. provis., in syn. Diholcos Haydenianus (Gray) Rydb. in Bull. Torr. Club 32: 664. 1905.

    Astragalus grallator (stilt-walker, from the abnormally elongate pedicels) Wats. in Zoë 3: 52. 1892.—"At Steamboat Springs, Routt County, Colorado."—Holotypus, collected in July, 1891, by Alice Eastwood, GH! isotypi, CAS, MINN. (2 sheets), US! Homalobus grallator (Wats). Rydb. in Bull. Torr. Club 32: 666. 1905.

    The Hayden milk-vetch is remarkable for the great number and small size of its nodding, retrorsely imbricated flowers which are disposed in elongate, cylindric racemes of a finger’s thickness. In New Mexico and southwestern Colorado the stems are usually diffuse and form low, leafy clumps from which the inflorescences arise vertically like candles; elsewhere the stems are as often erect and ascending in the manner of var. bisulcatus in the Prairie States. The hairs on the small, cross-reticulate pod vary from white to black.