Astragalus humistratusA.Gray

groundcover milkvetch

WFO wfo-0000169936 Accepted WFO 2026-06 8 photographs CC BY

Plate 1 figs. a–h · 8 separate observations

Astragalus humistratus, photographed by mark-groeneveld
fig. a mark-groeneveld, CC BY 4.0 / 2022-06-01 / obs. 202683490
Astragalus humistratus, photographed by Andrew Tree
fig. b Andrew Tree, CC BY 4.0 / obs. 193918467
Astragalus humistratus, photographed by Andrew Tree
fig. c Andrew Tree, CC BY 4.0 / obs. 189466407
Astragalus humistratus, photographed by Andrew Tree
fig. d Andrew Tree, CC BY 4.0 / obs. 187867868
Astragalus humistratus, photographed by Andrew Tree
fig. e Andrew Tree, CC BY 4.0 / obs. 186939663
Astragalus humistratus, photographed by Andrew Tree
fig. f Andrew Tree, CC BY 4.0 / obs. 185866242
Astragalus humistratus, photographed by Andrew Tree
fig. g Andrew Tree, CC BY 4.0 / obs. 185741871
Astragalus humistratus, photographed by Andrew Tree
fig. h Andrew Tree, CC BY 4.0 / obs. 185699209

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Native range 8 botanical countries

Regions where Astragalus humistratus is native: Arizona, Colorado, Mexico Northeast, Mexico Northwest, Nevada, New Mexico, Texas, Utah ArizonaColoradoMexico NortheastMexico NorthwestNevadaNew MexicoTexasUtah
Native distribution of Astragalus humistratus, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows.
RegionTDWG codeContinent
Arizona ARI NORTHERN AMERICA
Colorado COL
Mexico Northeast MXE
Mexico Northwest MXN
Nevada NEV
New Mexico NWM
Texas TEX
Utah UTA

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Where it actually grows measured, from 137 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -9.2 °C -4.7 °C -1.2 °C
Warmest month, mean daily high 25.2 °C 27.7 °C 31.8 °C
Annual rainfall 376 mm 473 mm 659 mm
Rainfall in the driest quarter 37 mm 56 mm 76 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 137 research-grade observations of Astragalus humistratus that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.

Also published as 16 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Astragalus datilensis (Rydb.) Tidestr.
  • Astragalus hosackiae Greene
  • Astragalus sonorae A.Gray
  • Astragalus sonorae var. tenerrimus (M.E.Jones) Kearney & Peebles
  • Batidophaca hosackiae (Greene) Rydb.
  • Batidophaca humistrata (A.Gray) Rydb.
  • Batidophaca humivagans Rydb.
  • Batidophaca sonorae (A.Gray) Rydb.
  • Batidophaca stipulacea Rydb.
  • Batidophaca tenerrima (M.E.Jones) Rydb.
  • Ctenophyllum humistratum (A.Gray) Rydb. ex A.Heller
  • Pisophaca datilensis Rydb.
  • Tium huministratum Rydb.
  • Tium humistratum (A.Gray) Rydb.
  • Tragacantha humistrata (A.Gray) Kuntze
  • Tragacantha sonorae (A.Gray) Kuntze

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.