Green Comet Milkweed
Asclepias viridiflora Raf.
A subtle, wide-ranging prairie milkweed with tight ball-shaped clusters of purely green flowers pressed against the stem. Enormously variable in leaf shape across its range, from broad and wavy to narrow and folded, which makes it one of the most confusing milkweeds to key out.
Also called Green Milkweed, Short Green Milkweed.
- Height
- 1 ft–3 ft
- Spread
- 1 ft–1.7 ft
- Flowers
- green
- Bloom
- May to August
- Light
- Full sun
- Soil moisture
- Dry
- USDA zones
- 3–9
- Leaves
- Opposite, elliptic
- Sap
- Milky latex
- Roots
- Deep taproot, resents transplanting
- Stratification
- 30 days cold-moist
- Range
- 38 states
When it flowers
Green Comet Milkweed blooms May to August, peaking in June and July.
How to identify it
- Flowers entirely green with no purple or white, in dense sessile or short-stalked clusters.
- Leaves thick and often with wavy margins; shape varies wildly between populations.
- Stems usually single, sometimes leaning; the whole plant is understated and easy to walk past.
Unfamiliar words are in the glossary, and the identification key will narrow a plant down from what you can see.
The parts that identify it
Ecology and wildlife value
Found on dry prairie, glades, sand and thin rocky soil across most of the continent. Used by monarchs, though its scattered distribution means it is rarely a major host. Wasps and small bees dominate the flowers.
Monarchs are not the only thing that will find it. Expect large milkweed bugs on ripening pods, oleander aphids on the stems, red milkweed beetles at the flowers and, in late summer, milkweed tussock moths. Everything that lives on milkweed.
Growing green comet milkweed
A collector’s plant rather than a landscape one. Needs perfect drainage and lean soil, and the taproot makes container-raised plants tricky to establish. Slow but very long-lived.
Seed needs about 30 days of cold-moist stratification. Deep taproot, resents transplanting. See how to plant milkweed seed for the full method.
Cautions
Standard milkweed cautions apply; not a significant livestock risk given its scattered occurrence. More on milkweed toxicity.
Where green comet milkweed grows
Recorded in 38 states: Alabama, Arkansas, Arizona, Colorado, Connecticut, Delaware, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Missouri, Mississippi, Montana, North Carolina, North Dakota, Nebraska, New Jersey, New Mexico, New York, Ohio, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Wisconsin, West Virginia, Wyoming.
County records from USDA PLANTS, public domain. Cross-check against BONAP and your regional flora before making management decisions.
References and further reading
Names, ranges and conservation status here are drawn from the databases below. Where those disagree with a regional flora, trust the flora.
- Plants of the World Online 1167930-2. Royal Botanic Gardens, Kew. Accepted name, authorship and global distribution.
- GBIF 3170313. Global Biodiversity Information Facility. Aggregated occurrence records.
- iNaturalist 158763. Community observations, photographs and phenology.
- Wikipedia. General-audience article on this species.
- BONAP county distribution map. Biota of North America Program. County-level range map.
- NatureServe Explorer. Conservation status ranks at global and state level.
- World Flora Online. Nomenclature and synonymy.
- Woodson, R. E. (1954). The North American species of Asclepias L.. Annals of the Missouri Botanical Garden 41(1): 1–211. The monograph the modern taxonomy of the genus still rests on. View
- Flora of North America Editorial Committee (eds.) (2026). Flora of North America North of Mexico. Oxford University Press, New York and Oxford. Accepted names, keys and descriptions for the North American flora. View
- Royal Botanic Gardens, Kew (2026). Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Nomenclature and global distribution, keyed to IPNI name identifiers. View
- Kartesz, J. T. (Biota of North America Program) (2026). North American Plant Atlas. BONAP, Chapel Hill, North Carolina. County-level distribution maps, the basis for the ranges generalized here. View
- USDA, NRCS (2026). The PLANTS Database. National Plant Data Team, Greensboro, North Carolina. State-level distribution, wetland status and nomenclature. View
- Agrawal, A. A. (2017). Monarchs and Milkweed: A Migrating Butterfly, a Poisonous Plant, and Their Remarkable Story of Coevolution. Princeton University Press. The standard general account of the milkweed and monarch relationship. View
Cite this page
This page is licensed CC BY 4.0. Quote it, adapt it and reuse it, including commercially, as long as you credit Milkweed USA and link back.
Milkweed USA. (2026). Green Comet Milkweed (Asclepias viridiflora). Retrieved DATE, from https://milkweedusa.com/species/green-comet-milkweed/
"Green Comet Milkweed (Asclepias viridiflora)." Milkweed USA, 2026, https://milkweedusa.com/species/green-comet-milkweed/. Accessed DATE.
Milkweed USA. "Green Comet Milkweed (Asclepias viridiflora)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/species/green-comet-milkweed/.
@misc{milkweedusa_speciesgreencometmilkweed,
title = {Green Comet Milkweed (Asclepias viridiflora)},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/species/green-comet-milkweed/},
note = {Accessed DATE}
}