Silphium perfoliatum L.

Common Cup Plant; Indian Cup; Carpenter's Square

Herb

Perennial

Vascular

Common Cup Plant is a native herbaceous perennial in the Sunflower family (Asteraceae). It occurs in western Alabama, primarily in the Black Belt region. Common Cup Plant is found on chalk prairies, on cedar glades, on marl outcrops, and in roadside ditches. It often occurs in areas with moist, basic soils derived from limestone. It is a perennial with fibrous roots from a short rhizome. The stems are 3-8 feet in height, unbranched below the inflorescence, green in color, square in cross section, and glabrous, hispid, or scabrous. Leaves are basal and cauline. The basal and lower stem leaves are large and usually absent at flowering. Basal leaves are petiolate, lanceolate to ovate in outline, scabrous to hispid, with toothed margins. Stem leaves are opposite, petiolate or sessile, lanceolate to ovate in outline, scabrous to hispid, with toothed margins. The upper stem leaves often form a “cup” that catches and holds rain water. Flowers are produced in heads. The heads are arranged in corymbs. Each head has 17-35 yellow ray flowers and 85-150 yellow disc flowers. The fruit is an achene. Birds are attracted to and drink from the water held in the cup leaves, and Goldfinches feed on the seed. Common Cup Plant is sometimes available from nurseries. It prefers a sunny site with moist, loamy soil. Plants can also be grown from seed, but will not usually flower until their second year. Plants can be used in pollinator gardens or in meadows.—A. Diamond.

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Native

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