Swamp Milkweed
Encyclopedia
Asclepias incarnata is a herbaceous
, perennial
plant species native to North America. It is found growing in damp to wet soils and also is cultivated as a garden plant for its attractive flower
s, which are visited by butterflies and other pollinators due to its copious production of nectar. Like most other milkweeds, it has sap
containing toxic chemicals, a characteristic that repels insects and herbivorous animals.
s. Typically, its stem
s are branched and the clump forming plants emerge in late spring after most other plants have begun growth for the year. The oppositely arranged leaves are 7 to 15 centimeters (2.75 to 6 inches) long and are narrow and lance-shaped, with the ends tapering to a sharp point.
The plants bloom in early to mid-summer, producing small, fragrant, pink to mauve (sometimes white) colored flowers in rounded umbel
s. The flower color may vary from darker shades of purple to soft, pinkish purple and a white flowering form exists as well. The flowers have five reflexed petals and an elevated central crown. After blooming, green seed pods, approximately 12 centimeters (4.5 inches) long, are produced that when ripe, split open. They then release light to dark brown, flat seed
s that are attached to silver-white silky-hairs ideal for catching the wind. This natural mechanism for seed dispersal is similar to that used by other milkweed plants.
, which feeds on the flowers and lays her eggs on the plants. The emerging caterpillars feed on the leaves.
The plants have specialized roots for living in heavy wet soils. The scented, thick, white roots are adapted to live in environments low in oxygen. Blooming occurs in mid to late summer and after blooming; long, relatively thin, rounded, pods are produced that grow uprightly. The pods split open in late summer to late fall, releasing seeds that are attached to silky hairs, which act as parachutes that carry the seeds on the currents of the wind.
Herbaceous
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
, perennial
Perennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
plant species native to North America. It is found growing in damp to wet soils and also is cultivated as a garden plant for its attractive flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s, which are visited by butterflies and other pollinators due to its copious production of nectar. Like most other milkweeds, it has sap
Sap
Sap may refer to:* Plant sap, the fluid transported in xylem cells or phloem sieve tube elements of a plant* Sap , a village in the Dunajská Streda District of Slovakia...
containing toxic chemicals, a characteristic that repels insects and herbivorous animals.
Description
Swamp milkweed is an upright, 100- to 150-centimeter (39- to 59-inches) tall plant, growing from thick, fleshy, white rootRoot
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
s. Typically, its stem
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...
s are branched and the clump forming plants emerge in late spring after most other plants have begun growth for the year. The oppositely arranged leaves are 7 to 15 centimeters (2.75 to 6 inches) long and are narrow and lance-shaped, with the ends tapering to a sharp point.
The plants bloom in early to mid-summer, producing small, fragrant, pink to mauve (sometimes white) colored flowers in rounded umbel
Umbel
An umbel is an inflorescence which consists of a number of short flower stalks which are equal in length and spread from a common point, somewhat like umbrella ribs....
s. The flower color may vary from darker shades of purple to soft, pinkish purple and a white flowering form exists as well. The flowers have five reflexed petals and an elevated central crown. After blooming, green seed pods, approximately 12 centimeters (4.5 inches) long, are produced that when ripe, split open. They then release light to dark brown, flat seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s that are attached to silver-white silky-hairs ideal for catching the wind. This natural mechanism for seed dispersal is similar to that used by other milkweed plants.
Habitat
Swamp milkweed prefers moisture retentive to damp soils in full sun to partial shade and typically, is found growing wild near the edges of ponds, lakes, streams, and low areas—or along ditches. It is one of the best attractors of the Monarch ButterflyMonarch butterfly
The Monarch butterfly is a milkweed butterfly , in the family Nymphalidae. It is perhaps the best known of all North American butterflies. Since the 19th century, it has been found in New Zealand, and in Australia since 1871 where it is called the Wanderer...
, which feeds on the flowers and lays her eggs on the plants. The emerging caterpillars feed on the leaves.
The plants have specialized roots for living in heavy wet soils. The scented, thick, white roots are adapted to live in environments low in oxygen. Blooming occurs in mid to late summer and after blooming; long, relatively thin, rounded, pods are produced that grow uprightly. The pods split open in late summer to late fall, releasing seeds that are attached to silky hairs, which act as parachutes that carry the seeds on the currents of the wind.
Cultivation
This species is cultivated frequently and a number of cultivars are available. They are used especially in gardens designed to attract butterflies. The nectar of the plant attracts many other species of butterflies and insects as well. The plants are also sold as freshly cut flowers, mostly for their long-lasting flower display, but sometimes, for the distinctive seed pods.External links
- Asclepias incarnata at Evergreen native plant database.
- Swamp Milkweed page from the Natural Resources Conservation ServiceNatural Resources Conservation ServiceThe Natural Resources Conservation Service , formerly known as the Soil Conservation Service , is an agency of the United States Department of Agriculture that provides technical assistance to farmers and other private landowners and managers.Its name was changed in 1994 during the Presidency of...
database.