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Common Milkweed Asclepias syriaca


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Common Milkweed
credit: Hardyplants

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Family: Asclepiadaceae, Milkweed view all from this family

Description Native herbaceous perennial. Grows to 6 feet tall from a rhizome. The stem and all parts of the plants produce a white latex when broken. The leaves are opposite, simple broad ovate-lanceolate, to 1 inch long and 1/2 inch wide, usually with an undulate margin and a red-colored main vein. They have a very short petiole and a velvety underside.

The flowers are grouped in several spherical umbels with numerous flowers in each umbel. The individual flowers are small, white-purple-pink, and fragrant, with five cornate hoods. The seeds are attached to long, white flossy hairs and encased in large follicles.

Warning All plants in the genus Asclepias are probably somewhat toxic, some fatally so, to both humans and animals. The sap of some causes skin irritation in humans. Sensitivity to a toxin varies with a personís age, weight, physical condition, and individual susceptibility. Children are most vulnerable because of their curiosity and small size. Toxicity can vary in a plant according to season, the plantís different parts, and its stage of growth; and plants can absorb toxic substances, such as herbicides, pesticides, and pollutants from the water, air, and soil.

Flower Summer, June - August.

Habitat It grows in sandy soils and appreciates lots of sunlight.

Range North America east of the Rocky Mountains; also naturalized in Oregon.

Discussion This plant is an important food source for the larvae of the Monarch butterfly. Depending on location, it may be an invasive or noxious weed. Other common names: Butterfly flower, Silkweed, Silky Swallow-wort, Virginia Silkweed.