A huge and very important subclass, with 15000 species. It contains the family Poaceae with 8000 species: these include not only the grasses of lawns and fields but the world's most important food crops; the cereals (wheat, barley, oats), rice, maize and sugar cane. Rushes and sedges are also in the Commelinidae.
Cyperaceae: Sedge family
In the Glasshouse pond are several sedge (Cyperus) species (right). These include the papyrus plant.
Commelinaceae: Spiderwort family
There are a number of examples in the Glasshouse of the family Commelinaceae, to which belong the familiar spiderwort houseplants: Tradescantia, Zebrina, Commelina and Rhoeo. This is a relictual family of the subclass, with relatively showy insect-pollinated flowers; the more derived families, like the grasses, are wind-pollinated.
Below: Oplismenus hirtellius.