# Aquatic Milkweed (Asclepias perennis)

> A small, soft, white-flowered milkweed of southern swamps and river floodplains that will grow in standing water and in shade, two things no other milkweed manages. Its seeds are unique in the genus: they have no silky floss.

Source: https://milkweedusa.com/species/aquatic-milkweed/  
Licence: CC BY 4.0 (Milkweed USA)

## Summary

A small, soft, white-flowered milkweed of southern swamps and river floodplains that will grow in standing water and in shade, two things no other milkweed manages. Its seeds are unique in the genus: they have no silky floss.

## Key facts

| Field | Value |
| --- | --- |
| Scientific name | Asclepias perennis Walter |
| Genus | Asclepias |
| Family | Apocynaceae |
| Common names | Aquatic Milkweed, Swamp White Milkweed, Thin-leaved Milkweed |
| Status | Native |
| Height | 1 ft–3 ft |
| Spread | 1 ft–2 ft |
| Flower color | white, pink |
| Bloom period | May to September |
| Light | Part shade, Shade, Full sun |
| Soil moisture | Wet |
| USDA zones | 6-9 |
| Leaf arrangement | opposite |
| Leaf shape | lanceolate |
| Sap | Milky latex |
| Root system | Fibrous, clump-forming and easy to move |
| Seed stratification | None required |
| Monarch value (0-5) | 4 |
| Garden value (0-5) | 4 |
| Nectar value (0-5) | 3 |
| US states recorded | Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Louisiana, Missouri, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia |

## Identification

- Grows in genuinely wet ground, often with its feet in water.
- Small white flowers, sometimes pink-flushed, in delicate clusters.
- Thin, soft, pointed leaves; the whole plant is fine-textured.
- Seeds lack the parachute of silk found in every other milkweed.

## Ecology

The key monarch host in southeastern floodplain forest and cypress swamp, and one of the few milkweeds that stays soft and edible through the humid southern summer.

## Growing

Superb for rain gardens, pond edges and shaded wet spots in the Southeast. Needs no stratification: sow fresh seed and it germinates in days. Blooms the first year.

## Cautions

Standard milkweed cautions.

## Questions

**What milkweed grows in Florida?**

Aquatic milkweed (A. perennis) for wet and shaded sites, pinewoods milkweed (A. humistrata) and butterfly weed for dry sand, and swamp milkweed in the north of the state. Florida gardeners should avoid tropical milkweed, which breeds monarchs year-round and spreads OE parasites.

## References

- Plants of the World Online: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:30270360-2
- GBIF: https://www.gbif.org/species/3170346
- iNaturalist: https://www.inaturalist.org/taxa/120152
- Wikipedia: https://en.wikipedia.org/wiki/Asclepias_perennis
- BONAP county map: https://bonap.net/MapGallery/County/Asclepias%20perennis.png
- NatureServe: https://explorer.natureserve.org/Search?searchTerm=Asclepias%20perennis

## Photographs

- Coastal Georgia Botanical Gardens, Swamp Milkweed Asclepias perennis (Michael Rivera, CC BY-SA 4.0): https://commons.wikimedia.org/wiki/File:Coastal_Georgia_Botanical_Gardens,_Swamp_Milkweed_Asclepias_perennis.jpg
- Asclepias perennis 222094081 (Alex Abair, CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_perennis_222094081.jpg
- Asclepias perennis 222094111 (Alex Abair, CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_perennis_222094111.jpg
- Asclepias perennis 222093949 (Alex Abair, CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_perennis_222093949.jpg
- Asclepias perennis 52080041 (Alex Abair, CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_perennis_52080041.jpg
- Asclepias perennis 52080032 (Alex Abair, CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_perennis_52080032.jpg
- Asclepias perennis 52080068 (Alex Abair, CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_perennis_52080068.jpg
- Asclepias perennis 52080048 (Alex Abair, CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_perennis_52080048.jpg

## How to cite

Milkweed USA. (2026). Aquatic Milkweed (Asclepias perennis). https://milkweedusa.com/species/aquatic-milkweed/