Cyperaceae
Leaf sheath closed or rarely open and then the perianth reduced to bristles or minute scales Cyperaceae
Flowers bisexual or unisexual but never enclosed in a utricle and never apparently separated into unisexual spikelets
Spikelets with 1–2 perfect flowers, other flowers male or sterile
Perianth scales or bristles absent
Glumes distichous (Fig. 46 i,l)
Spikelets solitary or in compact heads or umbels
Spikelets in narrow panicles or racemes