Astragalus knightii (Knight's milkvetch)
|USFWS||State of NM||USFS||BLM||Navajo Nation||State Rank||Global Rank||R-E-D Code||NMRPTC Status||Strategy Status|
Tufted perennial herb; stems numerous, ascending, 1-5 cm long, arising from a taproot; herbage gray-strigose with dolabriform hairs; stipules of the lower nodes connate; leaves pinnately compound, 2.5-8.5 cm long; stalks long, wiry, and sometimes persistent on the caudex; leaflets 9-15, narrowly elliptic or ovate-elliptic, 2-8 mm long; calyx 3-4 mm long, bell-shaped; petals whitish, lilac-tinged along the margins, lower petal purple tipped, banner bent upward 45 degrees, 5-6 mm long; pods pendulous, narrowly obovoid-ellipsoid, turgid or almost bladdery, 8-14 mm long, 4-6 mm wide, red spotted. Flowers May to early June.
Astragalus ceramicus can be distinguished from A. knightii by the presence of thread-like rhizomes and the absence of a taproot.
New Mexico, Sandoval County, middle Rio Puerco Valley.
Rimrock ledges of Dakota Formation sandstone in juniper savannah and grassland; 1,750-1,800 m (5,700-5,900 ft).
Presently known only from the Mesa Prieta area of the middle Rio Puerco drainage. The specific epithet honors Paul Knight who discovered this species while working as a botanist for the State of New Mexico.
Some populations are small and could be seriously impacted by road development, pipelines and mining activities.
*New Mexico Native Plants Protection Advisory Committee. 1984. A handbook of rare and endemic plants of New Mexico. University of New Mexico Press, Albuquerque.
Barneby, R.C. 1983. A new Astragalus from sandstone rimrock in New Mexico. Brittonia 35:109-110.
Isely, D. 1998. Native and naturalized Leguminosae (Fabaceae) of the United States. Monte L. Beane Life Science Museum, Brigham Young University, Provo, Utah.