''Asclepias verticillata'', the whorled milkweed, eastern whorled milkweed, or horsetail milkweed, is a species of

milkweed ''Asclepias'' is a genus of herbaceous, perennial, flowering plants known as milkweeds, named for their latex, a milky substance containing cardiac glycosides termed cardenolides, exuded where cells are damaged. Most species are toxic to humans ...

native to most of eastern North America and parts of western Canada and the United States.

Description

This is a perennial

herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...

with a single stem 6 inches to 3 feet tall. The very narrow, linear leaves are arranged in

whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral d ...

of 4–6 with short

internodes A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, stores nutrien ...

. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

is an

umbel In botany, an umbel is an inflorescence that consists of a number of short flower stalks (called pedicels) that spread from a common point, somewhat like umbrella ribs. The word was coined in botanical usage in the 1590s, from Latin ''umbella'' "p ...

of 7–20 greenish white flowers. Flowers are fragrant and bloom between June and September. Its native habitats include glades, dry prairies, dry slopes, dry open woods, pastures, fields, and roadsides. The Latin specific epithet ''verticillata'' is in reference to the leaves appearing in whorls.

Ecology

This species can

reproduce vegetatively Vegetative reproduction (also known as vegetative propagation, vegetative multiplication or cloning) is any form of asexual reproduction occurring in plants in which a new plant grows from a fragment or Cutting (plant), cutting of the paren ...

and does not depend on

pollinator A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains. Insects are the maj ...

s, but it does produce some

nectar Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists ...

, mostly in the early evening hours. Insect visitors to the plant include

wasp A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. Th ...

honeybee A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the current cosmo ...

s, and

lepidoptera Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...

ns such as

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

s and the

cabbage white Cabbage white or cabbage butterfly may refer to: * ''Pieris brassicae'', a Palearctic butterfly * ''Pieris rapae ''Pieris rapae'' is a small- to medium-sized butterfly species of the whites-and-yellows family Pieridae. It is known in Europe as ...

.Willson, M. F., et al. (1979)
Nectar production and flower visitors of ''Asclepias verticillata''.
''American Midland Naturalist'' 102(1) 23–35. Like other milkweed species, this plant is a host plant for the

monarch butterfly The monarch butterfly or simply monarch (''Danaus plexippus'') is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae. Other common names, depending on region, include milkweed, common tiger, wanderer, and black-veined brown. It ...

whose caterpillars feed on the leaves. The plant is toxic to

livestock Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animals ...

Uses

It was used as a

medicinal plant Medicinal plants, also called medicinal herbs, have been discovered and used in traditional medicine practices since prehistoric times. Plants synthesize hundreds of chemical compounds for various functions, including Plant defense against her ...

by Native American peoples. The

Choctaw The Choctaw (in the Choctaw language, Chahta) are a Native American people originally based in the Southeastern Woodlands, in what is now Alabama and Mississippi. Their Choctaw language is a Western Muskogean language. Today, Choctaw people are ...

used it to treat

snakebite A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs. Sometimes venom injection from the bite may occu ...

, the

Lakota Lakota may refer to: *Lakota people, a confederation of seven related Native American tribes *Lakota language, the language of the Lakota peoples Place names In the United States: *Lakota, Iowa *Lakota, North Dakota, seat of Nelson County *Lakota ...

and

Hopi The Hopi are a Native American ethnic group who primarily live on the Hopi Reservation in northeastern Arizona, United States. As of the 2010 census, there are 19,338 Hopi in the country. The Hopi Tribe is a sovereign nation within the Unite ...

used it to increase

breast milk Breast milk (sometimes spelled as breastmilk) or mother's milk is milk produced by mammary glands located in the breast of a human female. Breast milk is the primary source of nutrition for newborns, containing fat, protein, carbohydrates ( lacto ...

in nursing mothers, and the

Navajo The Navajo (; British English: Navaho; nv, Diné or ') are a Native American people of the Southwestern United States. With more than 399,494 enrolled tribal members , the Navajo Nation is the largest federally recognized tribe in the United ...

used it for nose and throat problems.''Asclepias verticillata''.
Native American Ethnobotany. University of Michigan, Dearborn.

References

verticillata Butterfly food plants Flora of Northern America Plants described in 1753 Taxa named by Carl Linnaeus {{Apocynaceae-stub Grassland plant species of Alabama