Virginia pepper grass

not listed

N5 - Secure

SNR - Unranked

not listed

FACU - Facultative upland

FACU - Facultative upland

FACU - Facultative upland

Virginia pepper grass is a 4″ to 20″ tall, erect, annual or biennial forb that rises on usually a single stem from a slender, branching taproot.

At first it forms a rosette about 6″ in diameter of basal leaves. The basal leaves are usually once lobed with a large, rounded, terminal lobe. When the plant is a biennial it overwinters in this form. Basal leaves are usually wilted by flowering time.

The flowering stems are erect or ascending. They are occasionally branched at the base, often branched in the upper third. They are covered, especially near the top, with minute, curved, mostly ascending hairs.

Lower stem leaves are alternate, inversely egg-shaped or linear, 1″ to 4″ long, and 3 ⁄16″ to ⅜″ wide. They are on short leaf stalks and are sometimes lobed. The leaf blades are tapered to almost heart-shaped at the base and taper to a point at the tip with straight sides along the tip. The upper and lower surfaces are usually hairless, sometimes sparsely hairy. The margins are sharply toothed.

Upper stem leaves are similar but smaller, linear, and stalkless but not clasping. The margins are usually untoothed.

The inflorescence is a dense, unbranched cluster (raceme) at the end of the stems and branches. The racemes are compact when in flower, but quickly elongate as the fruits develop, eventually becoming up to 4″ long. Typically, a few flowers are in bloom crowded at the top of the raceme, with developing and developed fruits below.

The individual flowers less than ⅛″ wide. There are 4 green, linear to narrowly elliptic sepals, and 4 white petals. The petals are as long to twice as long as the sepals. There is no floral scent.

The fruit is a flattened, 1 ⁄16″ to ⅛″ long, mostly circular, seed pod. It is widest at the middle. The tip is narrowly winged and has a broad, shallow notch. It is initially green, turning brownish when dry. It is on a stalk that is spreading or ascending.

4″ to 20″

White

Clasping pepper grass (Lepidium perfoliatum) upper stem leaves are broadly egg-shaped to circular and perfoliate or strongly clasping with auricles that surround the stem and overlap.

Field pennycress (Thlaspi arvense) fruits are much larger, 5 ⁄16″ to ¾″ long, and are broadly winged all around, not just at the tip.

Gardencress pepperweed (Lepidium sativum) fruits are on stalks that are closely ascending or almost erect. The fruits are larger, 3 ⁄16″ to ¼″ wide.

Prairie peppergrass (Lepidium densiflorum) is nearly indistinguishable when not in flower. The flowers either have no petals or have petals that are no longer than the sepals. The fruits are broadly inversely egg-shaped, widest above the middle.

Dry to moist. Prairies, bluff tops, fields, railroads, roadsides, disturbed sites. Full or partial sun.

May to July

This and other mustards (family Brassicaceae) produce chemical compounds when cells are damaged that are toxic to most animals, fungi, and bacteria.

Sources

2, 3, 4, 5, 7, 22, 28, 29, 30.

Native

Infructescence