Couch-Grass. Agropyron repens (L.) Beauv. Florets about 1 cm. long, 5-nerved at the short-awned apex: grain seldom produced and still less frequently found apart from the floral glume and palea, linear, about 4 mm. long, base abruptly acute, apex rounded, rounded on the back or outside, inside concave. Our worst weed. Introduced from Europe.

Fig 3. Wild Oat. Avena fauta L.

Wild Oat. Avena fauta L. Freed from chaff the floral glume is firm, rough, brown, thinly hairy, about 15 mm. long, awn from near the middle 2–4 cm. long with several firm twists, abruptly bent near the middle, the true grain seldom separated from the firmer floral glume. A bad weed in Oregon and California, seldom seen in Michigan.

Fig 4. Field Chess. Bromus arvensis (L.)

Field Chess. Bromus arvensis (L.) Not often seen in this country; floral glume 6–7 mm. long bearing an awn rather longer; grain much like that of B. secalinus which see. Introduced from Europe.

Fig 5. Soft Chess. Bromus hordeaceus L.

Soft Chess. Bromus hordeaceus L. (Bromus mollis). Floral glume extending beyond the grain, 5–7 nerved, 6–9 mm. long, grain rounded on the back, shape of a shallow boat, 6.5 mm. long, palea thin with comb-like teeth on the margins. Waste places, thin meadows. Introduced from Europe.

Fig 6. Smooth Brome-grass. Bromus racemosus L.

Smooth Brome-grass. Bromus racemosus L. Florets about 9 mm. long, awn 6–10 mm. long; longer, softer, thinner, with longer awn than found in florets of B. secalinus which see. Not often seen in this country. Introduced from Europe.

Fig 7. Chess Cheat. Bromus secalinus L.

Chess Cheat. Bromus secalinus L. Florets swollen a little above the middle, the floral glume rounded on the back, obscurely 7-nerved, 6–7 mm. long, an awn 3–4 mm. long, more or less; palea covering the concave side, each edge bearing a single row of stiff hairs; glume and palea closely adhering to the grain. Introduced from Europe. A weed in wheat fields.

Fig 8. Barren Brome Grass. Bromus sterilis L.

Barren Brome Grass. Bromus sterilis L. Floral glume minutely roughened, adhering to the grain; 5–7 nerved; 11–15 mm. long; compressed; concave in section. Introduced from Europe, becoming common in the state.

Fig 9. Sand-Bur. Bur-Grass. Cenchrus tribuloides L.

Sand-Bur. Bur-Grass. Cenchrus tribuloides L. Spikelets consisting of the grain and its coverings, broad oval, somewhat flattened, about 7 mm. long, thinly covered by stiff, straight, barbed, prickles, 2–5 mm. long, making a disagreeable and formidable bur, often common on sandy land. Native of this country.

Fig 10. Bermuda Grass. Cynodon Dactylon L., Pers., (Capriola Dactylon (L.) Kuntze).

Bermuda Grass. Cynodon Dactylon L., Pers., (Capriola Dactylon (L.) Kuntze). Floral glume enclosing the grain, smooth, light colored, oval to half-oval, 1.5 to 2 mm. long, in cross section with two long sides and a short side half as long; grain light brown, obovate to oval, a small nipple at the larger end.

The plant seeds in hot countries but not in cool, temperate regions; spreading chiefly by coarse, hard rootstocks. Introduced.

Fig 11. Small Crab-Grass. Digitaria humifusa Pers. Panicum lineare Kroach. Syntherisma linearis (Kroch.) Nash.

Small Crab-Grass. Digitaria humifusa Pers. Panicum lineare Kroach. Syntherisma linearis (Kroch.) Nash. Spikelets in the rough, before severe rubbing, ovoid or oblong, flattened, 2 mm. long, first glume minute, second and third as long as the spikelet, soft with very short hairs, one of them 3-nerved, the other 5-nerved; floret after severe rubbing, brown to black, smooth, floral glume of the rounded side curving over the edges below covering with their edges about two-thirds of the palea. Introduced from Europe; becoming troublesome on thin lawns.

Fig 12. Large Crab-Grass. Finger Grass. Digitaria sanguinalis (L.) Scop. Panicum sanguinale L. Syntherisma (L.) Nash.

Large Crab-Grass. Finger Grass. Digitaria sanguinalis (L.) Scop. Panicum sanguinale L. Syntherisma (L.) Nash. Spikelets before severe rubbing, oblong, acute, 2.5–3.5 mm. long, first glume on flattened side minute, second on rounded side about half as long as the spikelet, pubescent or nearly smooth, third glume more or less pubescent, 5–7-nerved; floret, after severe rubbing, smooth, edges of floral glume thin. Introduced from Europe. Roots very tough and coming from the lower joints.

Fig 13. Barnyard Grass. Echinochloa Crus-galli (L.) Beauv. Panicum Crus-galli L.

Barnyard Grass. Echinochloa Crus-galli (L.) Beauv. Panicum