Lithospermum occidentale

Native

Moderately dry. Prairies, open woods. Full sun.

June to July

Dull white or greenish white

12″ to 28″

This is a 12″ to 28″ tall, erect perennial forb that rises on several stems from a woody root.

The stems are erect, leafy, and often branched above the middle. They are covered with stiff, loose, white hairs.

Basal leaves are usually absent by the time the plant is in flower. Stem leaves are alternate, stalkless, unlobed, untoothed, and covered with stiff, loose, white hairs. They are lance-shaped to narrowly egg-shaped, uniform in size, 2″ to 3⅛″ long, and ½″ to ¾″ wide. There are 5 to 7 parallel veins recessed on the upper surface, raised (prominent) on the lower surface.

The inflorescence is a branched, crowded, one-sided, coiled cluster at the ends of the stems and branches.

The flowers are ⅓″ to ⅔″ long, 1½ to 2 times as long as wide, and tubular-shaped, converging to a point near the tip with straight sides along the tip. The 5 petals are dull white or greenish white and hairy. The style protrudes from the floral tube. These flowers mature reproductively well before the petals are developed.

The fruit is a white, smooth, shiny, marble-like nutlet over ⅛″ in diameter. They remain on the plant throughout the winter.

Softhair marbleseed (Lithospermum parviflorum) is the eastern subspecies. It is a taller plant, up to 48″ tall. The leaves are twice as large, up to 6″ long and 1½″ wide. The nutlet is dull and less than ⅛″ in diameter.

Taxonomy
The nomenclature for this species has been in flux for the last decade. It was originally listed as Onosmodium molle ssp. occidentale. In 1995 it was renamed Onosmodium bejariense var. occidentale (Turner, 1995). In 2009, based on a reassessment of DNA data, all of the species in the genus Onosmodium and four other genera were transferred to the genus Lithospermum. This subspecies, along with ssp. hispidissimum (softhair marbleseed), became synonyms of Lithospermum onosmodium. In December, 2011, the former subspecies of Onosmodium bejariense were raised to specific rank (Cohen and Davis, 2011). The new name, complete with author, is Lithospermum occidentale (Mack.) Weakley, Witsell & D. Estes.