Table of Contents for Curtiss’s Milkweed (Asclepias curtissii)
Curtiss’s Milkweed (Asclepias curtissii) is a herbaceous perennial that is native and endemic to the state of Florida in the United States. This plant is a host to the Queen (Danaus gilippus) and Monarch (Danaus plexippus) butterflies. Growing from 2 to 4 feet tall, this species grows in former wetlands, sandy areas, and places of disturbance and has pale green to white flowers that bloom from May to August. It is hardy in zones 8-10.
Taxonomy and Naming of Curtiss’s Milkweed (Asclepias curtissii)
Taxonomy
Curtiss’s Milkweed (Asclepias curtissii) was originally named and described by Asa Gray, an American botanist, in 1883. This species has been a number of names through time, but it is currently the same name since the description 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, curtissii, is presumably in honor of William Curtis, an earlier English botanist.
Common Name and Alternative Names
The common name comes from the last name of William Curtis, an earlier English botanist.
Physical Description of Curtiss’s Milkweed (Asclepias curtissii)
- Plant Type: This plant is a herbaceous perennial
- Height: 2 to 4 feet tall
- Stem: The stem is ascending to decumbent (Small 1903) and generally with few branches.
- Leaves: The leaves are opposite, simple, and oval, elliptic to ovate in shape (Woodson 1954). The leaves are 1 to 2 inches long and about 0.5 to 1.25 inches wide. The leaves are glabrous (Woodson 1954).
- Flower color: Pale green, pink (Weakley 2022), greenish-white to white.
- Blooming period: This plant blooms from April to August.
- Fruiting type and period: This plant has follicles that mature in the late summer and fall.
Range of Curtiss’s Milkweed (Asclepias curtissii) in the United States and Canada
This milkweed species is native to the southeastern United States. It is generally considered to be uncommon.
Habitat
This species grows in former wetlands, dry sandy scrub and pinelands (Woodson 1954), and places of disturbance. One source states this plant is an obligate to Florida scrublands (Hall and Gillespie 2004) and is endemic to the Central Florida Ridge (Judd and Hall 1984).
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. In particular this species has hosted the Zarucco Duskywing (Erynnis zarucco), the fiery skipper (Hylephila phyleus), the ocola skipper (Panoquina ocola), and the gray hairstreak (Strymon melinus) (Minno 1992).
Frequently Asked Questions about Curtiss’s Milkweed (Asclepias curtissii)
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 cite this species specifically, but milkweeds in general have been used for pharmaceuticals, fibers, and foods.
How is this plant distinguished from other milkweeds?
This species is similar to the green comet milkweed (Asclepias viridiflora), but differs in that green comet milkweed has strongly reflexed corolla lobes, whereas this species has reflexed rotate corollas. The flower color in green comet milkweed is also different having more yellowish flowers (Weakley 2022). Curtiss’s milkweed is also decumbent (Woodson 1954).
Is this plant invasive?
This plant has not been noted as being weedy and is limited range.
Is this plant deer resistant?
This plant has been noted as a favorite plant for deer browsing.
Gardening with Curtiss’s Milkweed (Asclepias curtissii)
Hardiness
This species is hardy roughly in zones 8-10. 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 can grow in full sun to partial-shade in well-drained soil.
References
- Hall, Jaclyn M. and Thomas W. Gillespie. 2004. Rarity and Conservation of Florida Scrub Plants. Florida Scientist 67: 9-17.
- Judd, Walter S. and David W. Hall. 1984. A new species of Ziziphus (Rhamnaceae) from Florida. Rhodora 86: 381-387.
- Minno, Marc C. 1992. Butterflies of the Archbold Biological Station, Highlands County, Florida. Journal of the Lepidopterists’ Society 46: 138-158.
- Small, John Kunkel. 1903. Flora of the southeastern United States; being descriptions of the seed-plants, ferns and fern-allies growing naturally in North Carolina, South Carolina, Georgia, Florida, Tennessee, Alabama, Mississippi, Arkansas, Louisiana and the Indian territory and in Oklahoma and Texas east of the one-hundredth meridian. (New York: self-published).
- Weakley, A.S., and Southeastern Flora Team 2022. Flora of the southeastern United States. University of North Carolina Herbarium, North Carolina Botanical Garden.
- Woodson, Robert E. 1954. The North American Species of Asclepias L. Annals of the Missouri Botanical Garden 41: 1-211.
