Asclepias asperula(Decne.) Woodson

Antelopehorn Milkweed

WFO wfo-0000551126 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h

Asclepias asperula, photographed by Michelle W. （鍾偉瑋）
fig. a Michelle W. （鍾偉瑋）, CC BY 4.0 / 2022-06-05 / obs. 204248816
Asclepias asperula, photographed by Michelle W. （鍾偉瑋）
fig. b Michelle W. （鍾偉瑋）, CC BY 4.0 / obs. 204249744
Asclepias asperula, photographed by Michelle W. （鍾偉瑋）
fig. c Michelle W. （鍾偉瑋）, CC BY 4.0 / obs. 204247054
Asclepias asperula, photographed by Michelle W. （鍾偉瑋）
fig. d Michelle W. （鍾偉瑋）, CC BY 4.0 / obs. 204246750
Asclepias asperula, photographed by mark-groeneveld
fig. e mark-groeneveld, CC BY 4.0 / obs. 200905888
Asclepias asperula, photographed by Michelle W. （鍾偉瑋）
fig. f Michelle W. （鍾偉瑋）, CC BY 4.0 / obs. 202067630
Asclepias asperula, photographed by Andrew Tree
fig. g Andrew Tree, CC BY 4.0 / obs. 200764768
Asclepias asperula, photographed by Reid Hardin
fig. h Reid Hardin, CC BY 4.0 / obs. 200608840

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.

Flowering n = 3,388 observations

Peak flowering in Apr, from 3,388 community-annotated observations worldwide. This is a global aggregate, not a forecast for your garden: the same species flowers on different dates in different hemispheres, and citizen-science records cluster near cities, at weekends, and in spring. Where a species has fewer than 30 annotated records we do not draw this chart at all.

Also published as 12 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.

  • Acerates asperula Decne.
  • Anantherix angustifolia Raf.
  • Anantherix decumbens Nutt.
  • Anantherix nuttaliana G.Don
  • Asclepias asperula var. asperula
  • Asclepias asperula var. decumbens (Nutt.) Shinners
  • Asclepias capricornu Woodson
  • Asclepias capricornu subsp. capricornu
  • Asclepias capricornu subsp. occidentalis Woodson
  • Asclepias decumbens (Nutt.) K.Schum.
  • Asclepiodora asperula (Decne.) E.Fourn.
  • Asclepiodora decumbens (Nutt.) A.Gray

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.

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