University of Minnesota Extension
/
612-624-1222
Menu Menu

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

Annual grass and perennial weed identification

Gerald R. Miller and Oliver E. Strand

Copyright © 2002 Regents of the University of Minnesota. All rights reserved.

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

Crabrass, 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

  • © 2013 Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy