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 in narrow panicles or racemes

Nut surmounted by a conical beak as long as the body. Uppermost flower perfect Tetraria

Nut surmounted by the thickened stylar base scarcely half as long as the body or almost obsolete. Lowermost flower perfect Baumea