Eleocharis filiculmis Kunth

Eleocharis filiculmis Kunth, Enum. PI. 2 : 144. 1837
Scirpus sulcatus Roth, Nov. PI. Sp. 30. 1821. Not S. sulcatus Petit-Thouars, 1811.
? Scirpus tenuiculns Schrad. ; Schultes in R. & S. Syst. Veg. Mant. 2 : 74. 1824. (Brazil.)
? Chaetocyperus tenuiculns Nees in Mart. Fl. Bras. 2^ : 96. 1842.
? Chaetocyperus emargiuatus Nees in Mart. Fl. Bras. 2^: 96. 1842. (Brazil.)
Scirpidium sulcatum Nees in Mart. Fl. Bras. 2^ : 98. 1842. (Bahia, Brazil.)
Limnochloa calyptrata Liebm. Vidensk. Selsk. Skr. V. 2: 244. 1851. (Mexico.)
Eleocharis calyptrata Steud. Syn. Cyp. 81. 1855.
Heleocharis Rothiana Bock. Flora 43 : 3. 1860.
Eleocharis sulcata Nees, Linnaea 9: 294. 1834 (nomen nudum); Bock. Linnaea 36: 445. 1870.
(Brazil.) Scirpus filiculmis Schrad.Griseb. Abh. Ges. Wiss. Gott. 24: 311. 1879. Heleocharis Balansaiana Bock. Flora 62: 159. 1879. (Pernambuco.) Heleocharis costaricensis Bock. Allg. Bot. Zeitschr. 2 : 34. 1896. (Costa Rica.) Heleocharis purpureo-vaginata Bock. Allg. Bot. Zeitschr. 2: 34. 1896. (Buenos Aires.)
Erect from an ascending caudex; culms 1.5-4 dm. high, flattened and sulcate, lightly punctate, rarely as much as 1 mm. wide ; sheath purplish-brown to stramineous, acute, sometimes slightly inflated at the apex ; spikelets ovoid-cylindric, 4-10 mm. long, many-flowered ; scales obtuse to emarginate, stramineous to reddish-brown, with a lighter keel and a prominently scarious margin; anthers 0.7 mm. long; style trifid; achene 1.0 mm. long (including the style-base), trigonous with sulcate angles, glistening white, often obscurely reticulate or brown-striolate ; style-base nearly as wide as the apex of the achene, irregularly pyramidal, often somewhat flattened, white to light brown, frequently with overhanging margins ; bristles white, usually equaling the achene.
Type locality : Brazil.
Distribution : Mexico to Panama ; Cuba ; Dominica ; tropical South America.