Fimbristylis autumnalis (L.) Roem. & Schult.

Fimbristylis autumnalis (L.) R. & S. Syst. 2: 97. 1817
Scirpus autumnalis L. Mant. 180. 1771. (Virginia.)
Scirpus mucronulatus Michx. Fl. Bor.-Am. 1:31. 1803. (Carolina mountains.)
Scirpus Michauxii Pers. Syn. Pl. 1 : 68. 1805. (Renaming of Scirpus mucronulatus Michx.) Trichelostylis geminata Nees, Linnaea 9: 290. 1834 (nomen nudum); Lindl. & Nees; Nees in
Mart. Fl. Bras. 2' : 79. 1842. Trichelostylis ttutcronulatiis Torr. Ann. Lye. N. Y. 3: 355. 1836. Fimbristylis Frankii Steud. Syn. Cyp. 111. 1855. (Ohio.) } Finibristylis microstachya Steud. Syn. Cyp. 113. 1855. (Brazil, Pohl.) Fimbristylis autumnalis Q gracilis Boek. Linnaea 37 : 39. 1871. Trichelostylis borealis Wood, Bot. & Fl. ed. 1871. 364. 1871. (Illinois, /. IVolf.) Fimbristylis Frankii var. brachyactis Fernald, Rhodora 11: 180. 1909. (Maine.) Fimbristylis autumnalis i. brachyactis Blake, Rhodora 20: 25. 1918. ? Fimbristylis autumnalis var. gracilis Kiikenth. Repert. Sp. Nov. 23: 196. 1926. (IVilldenoiv
1226, from the Orinoco.) Fimbristylis autumnalis var. mucromilata Fernald, Rhodora 37 : 398. 1935.
Cespitose glabrous annual; culms 1-4 dm. high, narrow, 0.5-1.0 mm. wide, diffuse or erect ; leaves flat, 0.5-2.5 mm. wide ; the bracts usually shorter than the decompound to nearly simple umbel ; spikelets ovoid to narrowly cylindric, sessile or peduncled ; scales ovatelanceolate, appressed, dull brown with a greenish keel, mucronate ; achenes obovate, 0.5 mm. long, the angles often costulate, translucent buff, smooth to faintly reticulate with horizontal cells (frequently verrucose at the base, sometimes throughout) ; style terete, not fimbriate, bulbous at the base, 1.0 mm. long below the 3 branches; stamens 1 or 2, the anthers 0.3 mm. long.
Type locality: Virginia {Clayton).
Distribution : Maine, west to Ontario and Minnesota, south to Florida, Oklahoma, and Texas; British Honduras (Schipp 903, Gentle 1961); Cuba.