Poaceae

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.

Spikelets bisexual or, if unisexual, then male and female very similar and in the same inflorescence

Rhachis not flattened and corky; spikelets not sunken in the rhachis

Spikelets or groups of spikelets subtended or surrounded by 1–several bristles which are simple or fused at the base to form a burr

No long hairs and bristles surrounding the base of the spikelet