Table of Contents for Side-Cluster Milkweed (Asclepias lanuginosa)
Side-Cluster Milkweed (Asclepias lanuginosa) is a herbaceous perennial that is native to the mid-western United States and Canada. This plant is a host to the Queen (Danaus gilippus) and Monarch (Danaus plexippus) butterflies. Growing from 0.5 to 4 (6) feet tall, this species has green to cream flowers that bloom from May to July. It is hardy in zones 4-7.
Taxonomy and Naming
Taxonomy
Side-Cluster Milkweed (Asclepias lanuginosa) was originally named and described by Thomas Nuttall, an American botanist, in 1818. Over the years it has been described and renamed, but it still officially has its original name. The species has kept this name since this time and is a member of the Dogbane Family (Apocynaceae).
Meaning of the Scientific and Common Names
Scientific Name
The genus name, Asclepias, is named for the Greek god of healing, Asklepios (Flora of Wisconsin). The species name, lanuginosa, means “woolly” in Latin. This name is apparently referring to the woolly (hairy) nature of the plant.
Common Name and Alternative Names
The common name comes from the position of the flowers. Other common names for this plant include woolly milkweed, not to be confused with the other woolly milkweed (Asclepias vestita) and hairy milkweed.
Physical Description
- Plant Type: This plant is a herbaceous perennial
- Height: 0.5 to 4 (6) – (Budd’s Flora 1987) feet
- Stem: The pubescent stem is spreading to ascending and not branched.
- Leaves: The leaves are alternate or maybe opposite, short-petiolate, simple, entire, and ovate to lanceolate in shape. The leaves are 1 to 3 inches long and about 0.4 to 2 inches wide.
- Flower color: green to cream
- Blooming period: This plant blooms from May to August.
- Fruiting type and period: This plant has follicles that mature in the late summer.
Range of Side-Cluster Milkweed (Asclepias lanuginosa) in the United States and Canada
This milkweed species is native to the mid-western United States and Canada. It is considered to be rare in all of its range except for the state of Minnesota.
Habitat
This species grows in prairies and sandhills.
Hosted Insects
This species is a host for the Monarch Butterfly (Danaus plexippus), the Queen Butterfly (Danaus gilippus).
Other Supported Wildlife
This species is a nectar source to other butterflies, skippers, bees, and wasps during the growing season. Birds also like this plant.
Frequently Asked Questions
Is this plant poisonous?
Like other milkweeds, it has cardiac glycosides (cardenolides) and is considered to be poisonous with ingestion.
Does this plant have any ethnobotanical uses?
The Native American Ethobotanical Database does not mention this plant specifically, but milkweeds in general have been used for pharmaceuticals, foods, and fibers.
How is this plant distinguished from other milkweeds?
This species is similar to green comet milkweed (Asclepias viridiflora), but green comet milkweed several lateral umbels, whereas this species milkweed has a solitary umbel that is terminal (Budd’s flora 1987).
Is this plant invasive?
This plant has not been shown to be invasive in the literature.
Gardening with Side-Cluster Milkweed (Asclepias lanuginosa)
Hardiness
This species is hardy in zones 4-7. If your garden is within these zones and you have the right growing conditions (soil, moisture and exposure), you may well be able to grow this plant. However, if planted outside of its range, the hosted species may not recognize the plant or be harmed by ingesting a different species with an unfamiliar chemical composition.
Optimal Conditions
This species grows best in places that have full sun and well-drained soils.
References
- J. Looman Research Station. 1987. Budd’s Flora of the Canadian Prairie Provinces. (Ottawa: Agriculture Canada).
- Woodson, Robert E. 1954. The North American Species of Asclepias L. Annals of the Missouri Botanical Garden 41: 1-211.
