Conoarundinphyta, or cone reeds, are flowering plants. They have hollow, triangular green stems that rise up from rhizomes, plugged at intervals called nodes. These rhizomes are sometimes thick and woody. Alternately, they can be spongy, starchy creepers. Leaves are leaves are spirally arranged in three ranks, parallel-veined and arise at the nodes. Each leaf is differentiated into a lower sheath hugging the stem for a distance and a blade with margin usually entire. The leaf blades of many conoarundinphyta are hardened with silica phytoliths, makeing the blades sharp enough to cut human skin. A membranous appendage or fringe of hairs, called the ligule, lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath. Blades grow at the base of the blade and not from growing tips.
Most conoarundinphyta are monoecious, but some are subdioecious or dioecious; all are wind-pollinated. Conoarundinphyta seeds develop inside a protective scaled cone. The cones are woody, and when mature the scales usually spread open allowing the seeds to fall out and be dispersed by the wind. In some, the cones disintegrate to release the seeds, and in others , the nut-like seeds are dispersed by animals which break up the specially adapted cones. Ripe cones may remain on the plant for a varied amount of time before falling to the ground.
The male cones produce microsporangia pollen. This is released and carried by the wind to female cones. Pollen grains produce pollen tubes. When a pollen grain lands near a female gametophyte, it undergoes meiosis and fertilizes the female gametophyte. The resulting zygote develops into an embryo, which along with its surrounding integument, becomes a seed. Eventually the seed, if conditions permit, grows into a new plant.
Conoarundinphyta also spread out from a parent plant. Growth habit describes the type of shoot growth present. There are three general classifications of growth habit present in grasses; bunch-type, stoloniferous, and rhizomatous.