Introduced. Perennial. Propagates by seeds and by tuber-bearing rootstoeks. Time of bloom: July to September. Seed-time: August to November. Range: New Brunswick to Minnesota and Nebraska, southward to

Florida and Texas; also on the Pacific Coast from California to

Alaska. Common in Europe and Asia and in tropical America. Habitat: Moist fields, banks of streams, and ditches.

In the South this plant is frequently cultivated for pasturing and for fattening hogs in autumn, those animals being very fond of its sweet, oily, and fleshy tubers. Unlike those of the preceding species, the tubers are usually clustered very near the parent plant, the scaly rootstocks being shorter and, unless the ground is vary soft, not far below the surface. (Fig. 35.)

Culms, stout, fifteen to thirty inches high, three-sided, light yellowish green. Leaves about the same length, one-fourth to one-half inch wide, with heavy mid-vein and slightly roughened edges. The involucre has three to six leaf-like bracts extending much beyond the rays of the umbel, which are often compound. Spikes straw-colored or pale yellow-brown, the whole plant being conspicuous for its light coloring, plainly visible at a distance among grasses. The scales of the spikelets are oblong-ovate, appressed at the base but loose at the tip, three to five-nerved, with narrow scarious margins. Achenes small, oblong ovoid, three-sided, light yellowish brown.

Fig. 35. - Chufa (Cyperus esculentus).

X 1/5.

Means Of Control

Drainage of the ground, followed by clean, late-continued hoe-cultivation which will prevent seed production and gradually starve the underground growth. Hogs may be of assistance in the beginning in cleansing a badly infested plot.