University of Minnesota Extension
www.extension.umn.edu
612-624-1222
 Menu  Menu

Extension > Garden > Yard and Garden > Weeds > Annual grass and perennial weed identification

Print Email Share

Annual grass and perennial weed identification

Gerald R. Miller and Oliver E. Strand

Descriptions of annual grass and perennial weed

Annual grass

Barnyardgrass

Leaves smooth and mostly hairless; no ligule; inflorescence a raceme-like panicle, spikelets bristly-hairy.

Barnyardgrass

Crabgrass, large

Leaves (sheath and blade) densely hairy, membranous ligule; inflorescence a digitate (finger-like) panicle; spikelets closely appressed to panicle.

Crabrass, large

Foxtail, giant

Leaf blades pubescent on upper surface; ligule a fringe of hairs; inflorescence a cylindrical head (compact panicle) about 3–5 inches long, drooping from the base; spikelets crowded, subtended by numerous bristles (usually three to six) which arise from the base of the spikelet.

Foxtail, giant

Foxtail, green

Leaf blades relatively hairless; ligule a fringe of hairs; inflorescence a cylindrical head (compact panicle) which is usually 3–4 inches long (but may be longer in robust green foxtail) and droops or nods from the tip; spikelets crowded, subtended by two to three bristles which arise from base of spikelet.

Foxtail, green

Foxtail, yellow

Leaf sheath flattened; leaf blades have long scattered whitish hairs near base; ligule a fringe of hairs; inflorescence a cylindrical head which is short (2–3 inches), narrow; spikelets crowded, subtended by yellow bristles (three to six) which arise from base; seed larger than giant or green foxtail, seed prominently cross-ribbed

Foxtail, yellow

Oat, wild

Leaf sheath hairy; leaf blade relatively smooth and free of hairs except along leaf margin near base; ligule prominent, membranous; inflorescence a spreading, true panicle; spikelets have two large glumes (chaffy bracts) which enclose two to three seeds; seeds (grains) are hairy toward base with bent and twisted awns.

Oat, wild

Panicum, fall

Leaves smooth and relatively hairless; ligule a fringe of hairs; stems zigzagged, nodes prominent; inflorescence a spreading panicle, culms often have several panicles arising from lower-leaf sheaths, these often not fully extended from boot; spikelets small, with three apparent glumes, the first short and blunt.

Panicum, fall

Proso millet, wild

Leaves (blades and sheath) densely hairy; ligule a fringe of hairs; inflorescence a spreading panicle; spikelets large (1/16-inch across) with three apparent chaffy glumes, the first half length and pointed at the tip; seed olive-green to black, shiny.

Proso millet, wild

Perennial Weeds

Quackgrass

Leaf sheaths hairy, open; leaf blades smooth or slightly pubescent; leaves bear a pair of claw-like auricles attached at top of leaf sheath; inflorescence a spike with spikelets attached directly to the central axis; several seeds crowded into each spikelet; plant has extensive underground whitish rhizomes (underground stems) from which new plants can arise.

Quackgrass

Artichoke, Jerusalem

Leaves opposite at base of plant becoming alternate above, leaves rough, toothed, large; flowers yellow, in heads, with darker center; stem rough hairy; roots bear fleshy tubers; plant erect, to 6 feet or more in height.

Artichoke, Jerusalem

Bindweed, field

Leaves alternate, arrowhead-shaped; flowers funnel-shaped, white to pinkish, about 1 inch in diameter, flower stalk bears a pair of small green stipules; seeds four per capsule, gray-brown, rough; plant vine-like and twining.

Bindweed, field

Bindweed, hedge

Leaves alternate, large, arrowhead shaped with cut-a-way corners at base; flowers white or pinkish, funnel-shaped, large, 2 inches in diameter; seeds large, rough, two to four per capsule; plant vine-like, twining.

Bindweed, hedge

Sowthistle, perennial

Leaves long, irregularly lobed, with prickles around leaf margin, leaves clasp stem at base (no leaf petiole); flowers yellow in heads from 1 to 1½ inches in diameter; seed reddish-brown, cylindrical, ribbed, spreading by tuft of hairs at tip; plants contain milky juice, plants erect.

Sowthistle, perennial

Nutsedge, yellow

Leaves three-ranked, narrow, grass-like, mostly basal; flowers yellowish or yellowish-brown, small in narrow spikelets on umbrella-like inflorescence; roots bear small, round vegetative tubers from which new plants can arise; plant erect.

Nutsedge, yellow

Thistle, Canada

Leaves with crinkled edges, very spiny and prickly; flowers in heads, lavender, about 3/4 inch in diameter; seeds brown, cylindrical, smooth, spreading by tuft of plume-like hairs; plant has extensive lateral root system from which plants spread in colonies, plant erect.

Thistle, Canada

  • © 2016 Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy