Cyperus iria L.

Common Name : Ricefield flatsedge
Family : Cyperaceae

HABIT

AN ANNUAL SEDGE, SOMETIMES BEHAVING AS A PERENNIAL. 8 TO 60 CM HIGH.

STEMS

THE CULMS ARE TUFTED, TRIANGULAR, GLABROUS, GREEN AND 0.6-3.0 MM THICK. THE ROOTS ARE NUMEROUS, SHORT AND YELLOWISH-RED.

LEAVES

LINEAR-LANCEOLATE, USUALLY ALL SHORTER THAN THE CULM, 1-8 MM WIDE, FLAT, AND SCABRID ON THE MARGIN AND MAJOR RIBS; LEAF SHEATHS ARE GREEN TO\ REDDISH-BROWN, MEMBRANEOUS AND ENVELOPE THE CULM AT THE BASE.

FLOWERS

INFLORESCENCE IS SIMPLE OR COMPOUND, USUALLY OPEN, 1-20 CM LONG AND 1-20 CM WIDE, WITH GROUPS OF SPIKES WHICH ARE EITHER SESSILE OR ON 0.5-15.0 CM LONG PEDUNCLES (RAYS). SPIKELETS ARE ERECT-SPREADING, CROWDED, 6-24-FLOWERED, 2-13 MM LONG, 1.5-2.0 MM WIDE, GOLDEN TO YELLOWISH-GREEN.

FRUITS

 NUTLET, 1.0-1.5 MM LONG, 0.6-0.7 MM WIDE, OBOVATE, TRIANGULAR IN CROSS SECTION, DARK-BROWN TO ALMOST BLACK; THE SURFACE IS ALMOST SMOOTH.