# Lemmon’s Milkweed (Asclepias lemmonii)

> A slim sky-island milkweed of shaded canyon bottoms in southeastern Arizona and southwestern New Mexico, with small green flowers flushed purple, appearing after the summer rains.

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

## Summary

A slim sky-island milkweed of shaded canyon bottoms in southeastern Arizona and southwestern New Mexico, with small green flowers flushed purple, appearing after the summer rains.

## Key facts

| Field | Value |
| --- | --- |
| Scientific name | Asclepias lemmonii A. Gray |
| Genus | Asclepias |
| Family | Apocynaceae |
| Common names | Lemmon’s Milkweed |
| Status | Native |
| Height | 8 in–2 ft |
| Spread | 8 in–1.5 ft |
| Flower color | green, purple |
| Bloom period | July to September |
| Light | Part shade, Full sun |
| Soil moisture | Dry, Average |
| USDA zones | 7-10 |
| Leaf arrangement | opposite |
| Leaf shape | lanceolate |
| Sap | Milky latex |
| Root system | Deep taproot, resents transplanting |
| Seed stratification | 30 days cold-moist |
| Monarch value (0-5) | 2 |
| Garden value (0-5) | 1 |
| Nectar value (0-5) | 2 |
| US states recorded | Arizona, New Mexico |

## Identification

- Slender stems in moist canyon shade rather than open desert.
- Small green flowers tinged with dull purple, few per cluster.
- Restricted to the higher sky-island ranges near the Mexican border.

## Ecology

A borderland species at the northern edge of a largely Mexican distribution, used by queens as well as monarchs.

## Growing

Not in cultivation.

## Cautions

Standard milkweed cautions.

## References

- Plants of the World Online: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:94393-1
- GBIF: https://www.gbif.org/species/3170287
- iNaturalist: https://www.inaturalist.org/taxa/158746
- BONAP county map: https://bonap.net/MapGallery/County/Asclepias%20lemmonii.png
- NatureServe: https://explorer.natureserve.org/Search?searchTerm=Asclepias%20lemmonii

## Photographs

- Lemmon’s Milkweed photographed in Huásabas, Son., México (M. Socorro González Elizondo, CC BY-SA 4.0): https://www.inaturalist.org/observations/202911704
- Lemmon’s Milkweed photographed in 80623 Badiraguato Sin., México (Public domain (CC0), CC0): https://www.inaturalist.org/observations/167434125
- Lemmon’s Milkweed photographed in Santa Cruz County, AZ, USA (Sue Carnahan, CC BY 4.0): https://www.inaturalist.org/observations/257931049
- Lemmon’s Milkweed photographed in Arizona, United States (Katja Schulz, CC BY 4.0): https://www.inaturalist.org/observations/8926073
- Lemmon’s Milkweed photographed in Cochise County, AZ, USA (Rachel Stringham, CC BY 4.0): https://www.inaturalist.org/observations/244828918
- Lemmon’s Milkweed photographed in 31993 Chih., México (Tereka Lasso, CC BY-SA 4.0): https://www.inaturalist.org/observations/126019696
- Lemmon’s Milkweed photographed in Cochise County, AZ, USA (Jeremiah Degenhardt, CC BY 4.0): https://www.inaturalist.org/observations/128144879
- Lemmon’s Milkweed photographed in E Carr Canyon Rd, Hereford, AZ, US (CK2AZ, CC BY 4.0): https://www.inaturalist.org/observations/235718984

## How to cite

Milkweed USA. (2026). Lemmon’s Milkweed (Asclepias lemmonii). https://milkweedusa.com/species/lemmons-milkweed/