Wavyleaf Basketgrass (Oplismenus undulatifolius) — identification, habitat & look-alikes

Wavyleaf basketgrass is a low, shade-loving grass native to southern Europe and Asia that has become an invasive pest in Mid-Atlantic forests. Its rippled leaves carpet shady forest floors, and in fall its sticky seeds hitch rides on boots, clothing, and animals.

Appearance

Growth form: A low perennial grass, roughly 4–12 in (10–30 cm) tall, with that creep along the ground, can sprawl for several feet, and root at the joints.
Leaves: Leaf blades are up to about 2.75 in (7 cm) long and clearly rippled across their width, like unfolded pleats. Stems are noticeably hairy, and the leaf sheaths are fuzzy.
Flowering time: Flowers and seeds from July into November in the Mid-Atlantic.

Look-alikes

Japanese stiltgrassMicrostegium vimineum

Look for wavyleaf basketgrass's pleat-like ripples across the leaf and its hairy stems with short white hairs. In fall, only wavyleaf has sticky seed heads.

Why they get mixed upBoth are invasive grasses that share the same shady eastern forests.

deertongueDichanthelium clandestinum

Hard to tell from leaves alone in photos; the pleat-like leaf ripples, creeping runners, and sticky fall seed heads point to wavyleaf basketgrass.

Why they get mixed upA native grass that Virginia land managers list among the plants most often mistaken for wavyleaf.

arthraxonArthraxon hispidus

Once seed heads appear they are easy to tell apart: only wavyleaf basketgrass has rippled leaves and long sticky .

Why they get mixed upAnother non-native grass with short, broad leaves.

Where it lives

Typical habitats: shady forests
forest edges
trailsides
Range: Native to a wide area of the Old World, from southern Europe through Asia, including Korea and Japan. It was first reported in the United States in 1996 near Liberty Reservoir in Howard County, Maryland. Since then it has spread through Maryland and Virginia (including Shenandoah National Park by 2004) and into Pennsylvania.
Preferred conditions: Grows well even in deep shade.
Flowering: Flowers Jul–Nov
Flowers Jul–Nov

Life cycle

Seed dispersal: In early fall the long awns turn sticky and cling to anything that brushes past.

Growing it

Propagation: Also spreads by runners, forming dense mats that can crowd out native plants.

Name and classification

About the name: Often listed as Oplismenus hirtellus subsp. undulatifolius, a subspecies of basketgrass; botanists differ on whether it is a separate species.