False Gromwell (Onosmodium Molle)

Features and Characteristics

Onosmodium molle is commonly called false gromwell because of a perceived similarity in appearance to some of the gromwells (Lithospermum). This species is a coarse, hairy, somewhat weedy, woody-based perennial that is native from New York to Louisiana and New Mexico north to Saskachewan. It is typically found growing in rocky prairies, glades, thickets and open rocky woods/fields. It grows in an upright shrubby clump to 2-3’ tall, and is noted for its terminal, drooping, bracteose flowering spikes and white nutlets that follow the flowers. Tubular flowers appear in late spring to early summer, featuring 5 creamy white to yellowish-green petals and a distinctive style that extends beyond the end of the flowering tube. Hard white nutlets follow the flowers. Nutlets usually persist on the dead foliage throughout the winter. Nutlets give rise to the additional common name of marbleseed for plants in this genus. Sessile, ovate to lance-shaped leaves. Steyermark lists three subspecies of this plant as being indigenous to Missouri: O. molle subsp. occidentale, O. molle subsp. subsetosum and O. molle subsp. hispidissimum.

Genus name means resembling the genus Onosma.