Tall perennial monoecious grasses with thick rootstocks, rather broad flat leaves and spicate or racemose inflorescence. Spikelets 1- or 2-flowered, in terminal or axillary, solitary or clustered, elongated spikes. Staminate spikelets in 2's at each node of the axis, 2-flowered. consisting of four scales, the two outer coriaceous or membranous, the two inner thinner, the palet hyaline; stamens 3. Pistillate spikelets in excavations at the lower joints of the spike, 1-flowered; stigmas exserted; style slender. Grain partly enclosed in the excavations of the spikes, covered in front by the horny exterior lower scale. [Name from the Greek, in allusion to the polished outer scales.]

About 7 species, in tropical and temperate America. Type species: Tripsacum dactyloides L.

1 Tripsacum L Syst Nat Ed 10 1261 1759 254

1. Tripsacum Dactyloides L. Gama- Sesame-Or Bull-Grass

Fig. 254

Coir dactyloides L. Sp. PI. 972. 1753. . Tripsacum dactyloides L. Sp. PI. Ed. 2, 1378. 1763. Tripsacum dactyloides var. monostachyum Wood, Class-book Ed. 2, 623. 1847.

Culms stout, erect, 4°-8° tall. Leaves smooth and glabrous; blades 1° or more long, 1/2-1 1/2' wide, long-acuminate, truncate or subcordate at the base; spikes terminal and in the upper axils, solitary or 2 or 3 together, 4'-9' long, the lower spikelets pistillate, the upper staminate and very numerous; outer scales of the staminate spikelets linear and obtuse, 3 1/2"-5 1/2" long, faintly many-nerved; exterior scale of the pistillate spikelets horny, shining, closely appressed in fruit.

In swamps or along streams, Rhode Island to Nebraska, south to Florida, Texas and Mexico, the southern Bahamas, Haiti and South America. June-Sept.