Table of Contents for Poke Milkweed (Asclepias exaltata)
Poke milkweed (Asclepias exaltata) is a haven in the forest for monarch butterflies, as well as, a source of toxins. In this post we delve into the fascinating world of the poke milkweed and look at its importance for the monarch butterfly and whether it can be incorporated into your garden. First we will look at its taxonomic history, then a description of the plant, it’s range and ecology, insects it hosts, and tips on its cultivation in your garden. By the end of the post, you will see poke milkweed, not just as a another plant in your garden, but as part of the intricate world of plants. Are you ready to learn about poke milkweed?
A brief Description: Poke Milkweed (Asclepias exaltata) is a herbaceous perennial that grows from the mid-west to eastern North America. This plant is a host to the Monarch (Danaus plexippus). It can grow to 6 feet tall and has green to white flowers that bloom from April to August. It is hardy in zones 3-9.
Taxonomy and Naming of Poke Milkweed (Asclepias exaltata)
Taxonomy
Poke milkweed (Asclepias exaltata) was named and described by Carl von Linnaeus, in 1753. It has kept this name since. This plant is a member of the Dogbane Family (Apocynaceae).
Synonyms
- Asclepias phytolaccoides
- Asclepias bicknellii
Meaning of the Scientific Names and Common Names
Scientific Name
The genus name, Asclepias, is named for the Greek god of healing, Asklepios (Flora of Wisconsin). The species name, exaltata, comes from the Latin word for “elevated”, possibly referring to the height of the plant.
Common Name and Alternative Names
The common name likely comes the resemblance of the plant to pokeweed (Phytolacca americana) and further evidence of this is a synonym, which is called A. phytolaccoides. The Illinois Wildflowers site states this as well. Another name for this plant is tall milkweed, which goes along with the species name.
Physical Description
- Plant Type: This plant is a herbaceous perennial.
- Height: 2 to 6 feet
- Stem: glabrous (hairless) or very slightly hairy and green to purplish in color
- Leaves: The leaves are opposite, simple, entire, and ovate to elliptic to egg-shaped. They range in size from 2 to 10 inches in length and 1 to 4 inches in width. The leaves are white underneath.
- Flower color: The flowers are white to green with some accents of rose, purple, or blue.
- Blooming period: This plant blooms from May to August.
- Fruiting type and period: This plant has follicles that mature in the late summer and fall.
Range of Poke Milkweed (Asclepias exaltata) in the United States and Canada
This species grows from the mid-west to the eastern United States and in Ontario and Quebec in Canada. It is considered to be rare in the states of Alabama, Delaware, Rhode Island, and Vermont and in the province of Quebec.
Habitat
This species grows in moist woods, thickets (House 1918 and Bohumil 1906), roadsides and wood edges (Witmer 1911), woodlands, and meadows.
Hosted Insects
This species is a host for the Monarch Butterfly (Danaus plexippus).
Other Supported Wildlife
This species produces abundant nectar and is used by other butterflies, bees, beetles, and birds in the late summer and fall.
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 shows that this plant has been used as a gastrointestinal aid.
How is this plant distinguished from others?
This milkweed is similar to the common milkweed (Asclepis syriaca), but has fewer flowers in a cluster than the common milkweed. Common milkweed is known to hybridize with this milkweed, producing plants that are intermediate between both (Illinois Wildflowers).
Is this plant invasive?
According to the Prairie Moon Nursery, this milkweed is among the least aggressive. This has been observed in the woods around Pennsylvania, where there is often one or only a few plants present when found. Poke milkweed has a taproot, so it does not spread by rhizomes.
Gardening with Poke Milkweed (Asclepias exaltata)
Add Poke Milkweed to Your Garden
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Overall Conditions in the Wild
This species grows best in moist soil where it can receive part shade to shade. According to Minnesota Wildflowers, this is among the most shade resistant of the milkweeds. This plant is often found on the borders of wooded areas and garden conditions should mimic this habitat for best results.
Garden Conditions Needed
- Plant Hardiness Zone: 3-9, 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.
- Exposure: This species can handle full sun but does better in places where it can get shading or dappled sunlight.
- Soils: Soils should be moist and well-drained and have organic matter throughout. Add compost or manure to sandy soils and sand or perlite to clayey soils. Soils can be acidic to slightly alkaline.
- When to Plant: Seeds should be planted at the last frost and pressed into the ground surface such that they still get light, which is needed for germination.
- Care of Plants: Plants should watered often during the first year in order to encourage rooting. Once established the plants are fairly tolerant of most conditions encountered in the wild.
References
- Bohumil, Shimek. 1906. Flora of Winneshiek County. Des Moines, IA. (Book)
- House, Homer. 1918. Wild flowers of New York. Memoirs of the New York State Museum no. 15.
- Witmer, Stone. 1911. The plants of Southern New Jersey; with especial reference to the flora of the Pine Barrens and geographic distribution of the species. Trenton, NJ. (Book)
- Woodson, Robert E. 1954. The North American Species of Asclepias L. Annals of the Missouri Botanical Garden 41: 1-211.
