This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Annual. Propagates by seeds. Time of bloom: May to July. Seed-time: June to August.
Range: Throughout eastern North America.
Habitat: Meadows, pastures, grain fields, roadsides, and waste places.
Stone Clover usually grows and is able to thrive on very dry, sandy, and gravelly soils, and it is a pity that it is not a better fodder plant. But its excessive hairiness causes cattle to dislike it and even makes it dangerous, particularly when eaten by horses, as the fuzzy flower-heads sometimes collect into felt-like, compact masses called phytobezoars, or hair-balls, closing the intestines and occasionally causing a very distressful form of death.
Stem six inches to a foot high, erect, slender, much branched, covered with fine, silky, gray hair. Leaves alternate palmately three-foliolate, with short petioles and narrow, awl-shaped stipules; leaflets narrowly oblong or wedge-shaped, about an inch in length, obtuse or often notched at the tips. Flowers in dense, nearly cylindrical heads, a half-inch to an inch long, on slender, terminal peduncles; corolla white or pinkish but hidden by the calyx-lobes, which extend far beyond it in five slender, awl-like points, thickly fringed with silky gray or pale reddish hairs. Pods very tiny, containing one or two seeds which are a frequent impurity of other clover seeds and of grasses and grain. (Fig. 163.)
Enrich and cultivate the ground, seeding heavily to other and better members of the Clover Family. When Stone Clover is cured with hay, the danger from hair-balls is averted by cutting before the heads are matured. Also such prevention of seeding will cleanse the ground of the weed, if persistently repeated until all dormant seeds have germinated and been thus destroyed.
Fig. 163. - Rabbit-foot Clover (Trifolium arvense). X1/3