Cyperus

 

 

 

 

 

 Cyperus polystachyos Rottb.

Distribution: Widespread around the world

Habitat: Weedy

Recognition:  One of the most common and conspicuous Cyperus species in our area.  Often 12"-24" tall. the stem triangular, the inflorescence a simple umbel (or with no rays), the spikelets flat, 1.3-1.6(2) mm wide, shaped like knife blades, oriented distally at 45 degrees. Scales usually 12-25, mucronate.  Stigmas 2. Achenes ca. 1 mm long.

Key to similar species:

1. Achene much longer than wide; spikelets 1.3-1.6(2) mm wide…C. polystachyos (very common and highly variable, the spikelets extremely variable in length)

1. Achene ellipsoid or ovate; spikelets > 2 mm wide…2

2. Mature achene black or brown, the surface covered with elongate cells…C. flavescens

2. Mature achene brown, the surface covered with square cells…C. lanceolatus

Florida status: Common, probably native