The following Participating Institutions are custodians for this species in the CPC National Collection:
The Arboretum at Flagstaff
The conservation of Astragalus humillimus is fully sponsored.
Joyce Maschinski, Ph.D. contributed to this Plant Profile.
Mancos milkvetch is a diminutive, tufted perennial that is found in rock crevices. The leaves have spines along their central veins that remain after the leaflets fall. The plant flowers in late April and early May producing pale lavender to purple blooms. (ESIS 2002) Reaching for a closer look at the pale lavender to purple flowers can be a prickly experience.
Astragalus humillimus was rediscovered near Farmington, New Mexico, in 1980. It was formerly known from only a single collection made in 1875. It is currently known from 13 sites, 10 in New Mexico, and 3 in Colorado. High mortality occurs during periods of extended drought, but the populations regenerate from seed during more favorable years. (New Mexico Rare Plant Technical Council 1999)
Distribution & Occurrence
- New Mexico
Cracks or eroded depressions on sandstone rimrock ledges and mesa tops in Point Lookout sandstone, which is a Cretaceous sandstone that is part of the larger Mesa Verde stratigraphic series; 1,500-1,800 m (5,000-6,000 ft.) in elevation. (New Mexico Rare Plant Technical Council 1999)
Associated plants include Oryzopsis hymenoides, Gutierrezia sarothrae, Yucca angustissima, and Artemisia tridendata. (USFWS 1985)
|Only four populations were known at the time of listing, totaling around 7,000 individuals. All known populations were located in New Mexico on Bureau of Land Management and Navajo Indian Reservation lands. (USFWS 1985) Since the time of listing, additional populations have been found both in New Mexico and Colorado.
There are now nine populations known to exist at thirteen sites that vary in size from 200 to 7700 plants. All the populations are in an area being intensively developed for energy resources. (NatureServe Explorer 2002)
Conservation, Ecology & Research
utility corridor maintenance
Tepedino, V.J. 2002. Section III. Environmental Monitoring. III.5 The Reproductive Biology of Rare Rangeland Plants and Their Vulnerability to Insecticides. Grasshoppers: Their biology, identification and management, User Handbook.