Tridens flavus (L.). Purpletop Habit: Tufted perennial. Culms: Erect, solitary, tufted, 1-1.5 m. high, flattened below. Blades: Elongate, 20-90 cm. long, upper shorter, 3-12 mm. wide, tapering, generally smooth except rough margined. Sheaths: The upper shorter than the internodes, the lower overlapping, flattened, especially the lower ones, pubescent at the throat and collar, otherwise glabrous. Ligule: A ring of very short hairs. Inflorescence: Panicle terminal, showy, loose and open, 15-35 cm. long, usually purple to finally nearly black, rarely yellowish, the slender branches spreading to drooping, naked below, the axils pubescent, the axis, branches, bractlets and pedicels viscid. Spikelets: 5-9 mm. long, 5-8-flowered, slightly compressed, green or purplish, the flowers perfect, or the upper one staminate, rachilla disarticulating above the glumes and between the florets. Glumes: Thin, subacute, mucronate, 1-nerved, unequal, 2-4 mm. long, shorter than the lowest floret. Lemmas: About 3-4 mm. long, 3-nerved, the 3 nerves excurrent, pubescent on the callus and lower half of keel and margins. Palea: A little shorter than the lemma, 2-toothed, ciliate on the nerves, somewhat bowed out below. Fruit: Grain concavo-convex. Habitat: Fields, prairie and open woods. July-September. Kansas Range: East two thirds. Synonyms: Tridens flavus (L.) A.S. Hitchc. var. flavus