# Slimleaf Milkweed (Asclepias stenophylla)

> A tall wand of a plant with grass-fine leaves and creamy-green flowers clustered tight against the stem, scattered through unplowed tallgrass and mixed-grass prairie.

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

## Summary

A tall wand of a plant with grass-fine leaves and creamy-green flowers clustered tight against the stem, scattered through unplowed tallgrass and mixed-grass prairie.

## Key facts

| Field | Value |
| --- | --- |
| Scientific name | Asclepias stenophylla A. Gray |
| Genus | Asclepias |
| Family | Apocynaceae |
| Common names | Slimleaf Milkweed, Narrow-leaf Green Milkweed |
| Status | Native |
| Height | 1.5 ft–3.3 ft |
| Spread | 10 in–1.5 ft |
| Flower color | cream, green |
| Bloom period | June to August |
| Light | Full sun |
| Soil moisture | Dry |
| USDA zones | 4-8 |
| Leaf arrangement | alternate |
| Leaf shape | threadlike |
| Sap | Milky latex |
| Root system | Deep taproot, resents transplanting |
| Seed stratification | 30 days cold-moist |
| Monarch value (0-5) | 3 |
| Garden value (0-5) | 2 |
| Nectar value (0-5) | 3 |
| US states recorded | Arkansas, Colorado, Iowa, Kansas, Louisiana, Missouri, Montana, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, Wyoming |

## Identification

- Extremely narrow alternate leaves, sometimes eight inches long and only a few millimeters wide.
- Flowers greenish-cream in small axillary clusters up the stem.
- Reliable indicator of high-quality remnant prairie.

## Ecology

A prairie-remnant specialist; its presence usually signals ground that has never been plowed.

## Growing

Rarely available; needs lean prairie soil and patience.

## Cautions

Standard milkweed cautions.

## References

- Plants of the World Online: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:94664-1
- GBIF: https://www.gbif.org/species/3170321
- iNaturalist: https://www.inaturalist.org/taxa/158760
- Wikipedia: https://en.wikipedia.org/wiki/Asclepias_stenophylla
- BONAP county map: https://bonap.net/MapGallery/County/Asclepias%20stenophylla.png
- NatureServe: https://explorer.natureserve.org/Search?searchTerm=Asclepias%20stenophylla

## Photographs

- Asclepias stenophylla 141042195 (Samuel A. Schmid, CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_stenophylla_141042195.jpg
- Slimleaf Milkweed photographed in Plymouth County, IA, USA (timharris, CC BY 4.0): https://www.inaturalist.org/observations/167765300
- Slimleaf Milkweed photographed in 66502, Manhattan, KS, US (Ryan Donnelly, CC BY 4.0): https://www.inaturalist.org/observations/28082061
- Slimleaf Milkweed photographed in Ashland, KS 66502, USA (Ethan Rose, CC BY 4.0): https://www.inaturalist.org/observations/233020874
- Slimleaf Milkweed photographed in 7146–7178 I-20 Service Rd, Aledo, TX, US (Sam Kieschnick, CC BY 4.0): https://www.inaturalist.org/observations/30655176
- Slimleaf Milkweed photographed in Osage, Oklahoma, United States (Emily Geest, CC BY 4.0): https://www.inaturalist.org/observations/71066498
- Slimleaf Milkweed photographed in Texas, US (CH Hemphill, CC BY 4.0): https://www.inaturalist.org/observations/220574960
- Slimleaf Milkweed photographed in Minnesota, US (Rose Zappa, CC BY 4.0): https://www.inaturalist.org/observations/102126234

## How to cite

Milkweed USA. (2026). Slimleaf Milkweed (Asclepias stenophylla). https://milkweedusa.com/species/slimleaf-milkweed/