FIG. 5. Tickle Grass (Panicum capillare). Common in fields and gardens, etc. (Photographed by Hart.)

reene

+

Distribution.-Old witch grass is common throughout the state, frequently as a weed. It is variable, the form occurring in cultivated fields being stout and hispid; but when occurring in moist meadows and old lake beds it has slender and somewhat capillary branches. In Iowa it is quite common in Plymouth, Woodbury, Muscatine, Story, Emmet, Franklin, Clinton, Carroll, Crawford, Pottawattamie, Scott and other counties.

Extermination.-This annual grass is easily exterminated by cultivation. It seldom gives trouble in well cultivated corn fields. It might be well also, when the weed is abundant, to rotate with some leguminous crop.

Sprouting Crab Grass (Panicum dichotomiflorum Mx.).

Description. A smooth, usually much-branched annual with stems 2-4 or 6 ft. tall, rather coarsely spreading or ascending (rarely erect); long, flat leaves and diffuse terminal and lateral panicles; sheaths smooth, lax, somewhat flattened; ligule ciliate; leaf-blade 6-12 or 24 in. long, 2-10 lines wide, acute, scabrous on the margins and sometimes also on the prominent nerves, rarely pilose on the upper surface; panicles pyramidal, 4 or 5-12 or 15 in. long, the primary and secondary branches spreading, scabrous; spikelets rather crowded upon short, appressed and scabrous pedicels, lanceolate-ovate; acute 1-112 lines long, smooth, green or purplish; lowest glume embracing the base of the spikelet, usually obtuse and nerveless, rarely 1-3-nerved, 14-1/3 as long as the nearly acute 5-7-nerved second and third glumes, the latter having sometimes a hyaline palea in its axil; floral glume elliptical, subacute, smooth and shining, a little shorter than the larger outer glumes; anthers saffron yellow.

Distribution.-Widely distributed in eastern North America, common in many parts of Iowa, as Ames, Des Moines, Sioux City, Council Bluffs, Davenport, Eddyville.

Extermination.-Prevent the formation of seed and give thorough cultivation.

FIG. 6. Sprouting Crab Grass (Panicum dichotomiflorum); a, b, c, spikelets;

d, e, flowering glume. Widely distributed in the state.

Barnyard Grass (Echinochloa crusgalli (L.) Beauv.).

Description.-A coarse, ascending, leafy annual 1-5 ft. high, with wide leaves; spike 1-3 in. long, crowded in a dense panicle;

FIG. 7.

culms frequently branched near the base; sheaths loose, smooth or sometimes hispid; leaves broad and flat, 6 in.-1 ft. or more long; smooth or roughened, margin roughened; spikelets densely and irregularly crowded in several rows along one side of the spikelike branches of the panicle, 11⁄2 lines long, outer glume or bract from 14-2 the length of the spikelets, second and third glumes smooth, pubescent or hispid along the nerves, fourth glume smooth, awnless or short awn-pointed.

Distribution.-Barnyard grass is native to Iowa, also to other parts of North America, and is quite generally distributed, particularly in barnyards, on shores of lakes, streams and in gardens, but is most abundant in low places.

Extermination-By thorough cultivation and preventing the formation of seeds.

Chemical Composition.-Chemical analyses of this grass have been reported from Iowa, North Carolina, South Dakota and Mexico. Weems reports the following composition from Iowa material.

Pigeon Grass, Foxtail (Setaria glauca (L.) Beauv.).. Description-An erect annual 1-21⁄2 ft. high; with flat leaves; bristly cylindrical spike, from 1-3 in. long; heads slender; bristles tawny yellow; small seeds conspicuously cross-striated and easily distinguished from the next species because of their larger size and by the cross-striation.

Distribution. This weed is quite generally distributed in the United States, particularly in eastern states. It occurs everywhere in the state of Iowa, particularly in corn fields, where it comes up abundantly, after the corn is "laid by:" also in gardens and in pastures, especially in the fall.