Perianth segments 0–3, usually 2; flowers grouped into a characteristic spikelet (Fig. 48) Poaceae
Spikelets unisexual, male and female markedly different and in different inflorescences; plants monoecious or dioecious
Female flowers arranged in a globular head 20–30 cm diam. Plants dioecious. Stoloniferous perennials on coastal sand dunes.
Female flowers not arranged in a globular head