# Longhood Milkweed (Asclepias macrotis)

> A slender limestone-canyon milkweed of west Texas, New Mexico and southern Colorado, with thread-like leaves and small pale flowers whose unusually long hoods give it its name.

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

## Summary

A slender limestone-canyon milkweed of west Texas, New Mexico and southern Colorado, with thread-like leaves and small pale flowers whose unusually long hoods give it its name.

## Key facts

| Field | Value |
| --- | --- |
| Scientific name | Asclepias macrotis Torr. |
| Genus | Asclepias |
| Family | Apocynaceae |
| Common names | Longhood Milkweed |
| Status | Native |
| Height | 8 in–1.7 ft |
| Spread | 10 in–1.7 ft |
| Flower color | green, cream |
| Bloom period | April to August |
| Light | Full sun |
| Soil moisture | Dry |
| USDA zones | 6-9 |
| Leaf arrangement | opposite |
| Leaf shape | threadlike |
| 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, Colorado, New Mexico, Texas |

## Identification

- Very long, projecting hoods on small greenish flowers.
- Wiry sprawling stems with thread-fine opposite leaves.
- Restricted to limestone outcrops and rocky canyon slopes.

## Ecology

A localised desert-canyon species of limited but real value to monarchs and queens moving through the Southwest.

## 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:94433-1
- GBIF: https://www.gbif.org/species/3170310
- iNaturalist: https://www.inaturalist.org/taxa/121660
- Wikipedia: https://en.wikipedia.org/wiki/Asclepias_macrotis
- BONAP county map: https://bonap.net/MapGallery/County/Asclepias%20macrotis.png
- NatureServe: https://explorer.natureserve.org/Search?searchTerm=Asclepias%20macrotis

## Photographs

- Asclepias macrotis - Michelle W 02 (Michelle W. (鍾偉瑋), CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_macrotis_-_Michelle_W_02.jpg
- Asclepias macrotis - Michelle W 01 (Michelle W. (鍾偉瑋), CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_macrotis_-_Michelle_W_01.jpg
- Asclepias macrotis - Michelle W 03 (Michelle W. (鍾偉瑋), CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_macrotis_-_Michelle_W_03.jpg
- Asclepias macrotis - Michelle W 04 (Michelle W. (鍾偉瑋), CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_macrotis_-_Michelle_W_04.jpg
- Asclepias macrotis - Michelle W 05 (Michelle W. (鍾偉瑋), CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_macrotis_-_Michelle_W_05.jpg
- Asclepias macrotis - Michelle W 06 (Michelle W. (鍾偉瑋), CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_macrotis_-_Michelle_W_06.jpg
- Asclepias macrotis - Michelle W 07 (Michelle W. (鍾偉瑋), CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_macrotis_-_Michelle_W_07.jpg
- Asclepias macrotis - Michelle W 09 (Michelle W. (鍾偉瑋), CC BY 4.0): https://commons.wikimedia.org/wiki/File:Asclepias_macrotis_-_Michelle_W_09.jpg

## How to cite

Milkweed USA. (2026). Longhood Milkweed (Asclepias macrotis). https://milkweedusa.com/species/longhood-milkweed/