Species Information

Kingdom: Plantae
  Phylum: Anthophyta
    Class: Dicotyledoneae
      Order: Fabales
        Family: Fabaceae
          Genus: Astragalus
            Species: castetteri

Castetter Milkvetch - Astragalus castetteri

Castetter Milkvetch

Image courtesy of New Mexico Rare Plants

614111

Species Extent (New Mexico)

General Description

Rhizomatous perennial; foliage strigose; stems 2-4 dm, clustered, ascending or decumbent; leaves 4-10 cm; leaflets 13-25, obovate to narrowly oblong, 5-15 mm long, 2-6 times longer than wide, flat or folded, often glabrate above; lower stipules connate; inflorescences compact, often within foliage, with 10-20 spreading or declined pea-like flowers, axis lengthening in fruit; calyx tube cylindric, 6-7 mm, lobes 2-3.5 mm; corolla 14-18 mm, purple or red-pink, banner curved back through 45, keel curved inward about 90; seeds numerous; pods usually humistrate (lying on the ground), stipitate, the stipe 1.5-3 mm long, one-celled (no septum), persistent, dehiscent, body bladdery-inflated, ovoid or ellipsoid-acuminate, subterete, 2-3 cm long, 1-1.6 cm wide, walls membranous-papery, almost transparent, strigulose or puberulent, often red-mottled. Flowers April-May.

Status

Global Rank: G3

State Rank: S3

Rank Metadata
State Rank: S3 Rank Changed: 11/10/1990
Rank Reviewed: 06/27/2025
Reason: Endemic to NM, this species has a narrow range with only 9 known EOs and few collections overall. More research is needed on abundance and threats. However, most occurrences are well protected on a remote, closed-to-the-public wildlife refuge. The remaining occurrences are not protected, but are still in relatively remote locations.
 
Ecological Factors
Specificity: Moderate. Generalist or community with some key requirements scarce. Range Extent: 1000-5000 square km (about 400-2000 square miles)
Occurences: 6 - 20 Population Size: N/A
Area of Occupancy: N/A Threat Summary: N/A

State Status:

Federal Status:

USFS Status:

BLM Status: BLM WATCH

SWAP Status:

NMRP Strategy Status: Strategy Species

Observations in Natural Heritage New Mexico Database

Number of Subpopulations: 9

Number of Mapped Locations: 24

Number of Observations: 32

Observation date range: 04-27-1937 to 04-27-2010

View More Information about this species at:
  NatureServe Explorer
  New Mexico Rare Plants Website
  Environmental Conservation Online System (ECOS)

Species Related Publications

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