Asclepias perennisWalter

Aquatic Milkweed

WFO wfo-0000551634 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h

Asclepias perennis, photographed by evangrimes
fig. a evangrimes, CC BY 4.0 / 2022-06-02 / obs. 203845714
Asclepias perennis, photographed by evangrimes
fig. b evangrimes, CC BY 4.0 / obs. 203845542
Asclepias perennis, photographed by evangrimes
fig. c evangrimes, CC BY 4.0 / obs. 203845597
Asclepias perennis, photographed by Jody Shugart
fig. d Jody Shugart, CC BY 4.0 / obs. 205675724
Asclepias perennis, photographed by Cody Stricker
fig. e Cody Stricker, CC BY 4.0 / obs. 160110324
Asclepias perennis, photographed by natalie
fig. f natalie, CC0 1.0 / obs. 178585899
Asclepias perennis, photographed by Samuel A Schmid, PhD, PWS
fig. g Samuel A Schmid, PhD, PWS, CC BY 4.0 / obs. 201064315
Asclepias perennis, photographed by Katie Kucera
fig. h Katie Kucera, CC BY 4.0 / obs. 170594980

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 = 877 observations

Peak flowering in Jun, from 877 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 11 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.

  • Asclepias debilis Michx.
  • Asclepias lancifolia Raf.
  • Asclepias laxiflora Perr. ex Colla
  • Asclepias matelea Nutt.
  • Asclepias parviflora Aiton
  • Asclepias parviflora var. latifolia Raf.
  • Asclepias parvifolia Pursh ex Decne.
  • Asclepias parvula (A.Gray) Vail
  • Asclepias perennis var. parvula A.Gray
  • Asclepias pulchella Salisb.
  • Matelea laevis Nutt.

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.