Kerrie L. Kyde, MD DNR

Wavyleaf Basketgrass

Oplismenus hirtellus ssp. undulatifolius (Ard.) U. Scholz
Grass family (Poaceae)

Origin: southern Europe and southeast Asia

Background
It was first discovered in Maryland in 1996 along the Patapsco River in Baltimore County and is spreading rapidly.

Distribution and Habitat
Wavyleaf basketgrass has been found in six counties in Maryland (Anne Arundel, Baltimore, Carroll, Howard, Montgomery and Prince Georges) and in counties in Virginia (Fairfax, Fauquier, Loudon, Madison, and Rockingham). It is highly shade-adapted and is found in forested areas from the margins to interior.

Ecological Threat
Wavyleaf grows low to the ground and spreads across the forest floor displacing native plant species completely or nearly so. It often occurs with Japanese stiltgrass. An urgent effort is underway to eradicate this fast-spreading invasive that has the potential to become much more widespread.

Description and Biology

• Plant: low-growing, shallow-rooted perennial grass; produces long stolons; branches and roots at the lower stem nodes.
• Leaves: flat, about ½ in. wide by 1½-4 in. long; deep green with undulating ripples across the leaf surface; leaf sheath and stem are noticeably hairy, with short hairs.
• Flowers, fruits and seeds: flowers are in spikelets that alternate along the flowering stalk; spikelets have glumes (lower bracts) with very long awns (extended pointed tips) that are sticky; late September into October.
• Spreads: by seed; sticky substance produced by the awns facilitates adherence to animal fur, human clothing and shoes, tires and other objects.
• Look-alikes: two native subspecies of basketgrass (Oplismenus hirtellus ssp. fasciculatus and O. h. ssp. setarius) occur in southern and southeastern U.S. but are not known to occur in the mid-Atlantic region. O. h. ssp. setarius, its closest relative, setarius, has only a few hairs, if any. Native deer-tongue panicgrass (Dicanthelium clandestinum) and small carpetgrass (Arthraxon hispidus) resemble wavyleaf but grow in upright clumps and their leaves are not rippled.

Prevention and Control
Do not purchase or plant this or any basketgrass in the mid-Atlantic states. Stay out of infested areas from August through November to prevent seed dispersal. If you work in an infested area, be thorough in removing all seeds from shoes, clothing and equipment prior to leaving (see Control Options).

Native Alternatives
Deer-tongue grass (Dichanthelium clandestinum), bottlebrush grass (Elymus hystrix) and many other native grasses are available.