Members can be recognized as largemarshherbs with alternate two-ranked leaves and a brownish compactspike ofunisexualflowers. The plants have creeping rhizomes.[3]
The male flowers either lack a perianth or have six scales. They may also have club shaped threads or wedge or spatula shaped scales that are intermingled with the flowers. They have between two and seven stamens.[3]
The female flowers have a perianth of fine hairs or scales. These may be accompanied by slender bracteoles. The ovary is one chambered and contains a single pendulous ovule. The style is simple and the stigma simple and long.[3]
The fruit may or may not be stalked and the pericarp may be thick or thin. The seeds are endospermous with a cylindric embryo.[3]
TheAPG II system, of 2003 (unchanged from theAPG system, 1998), also recognizes this family, and assigns it to the orderPoales in the cladecommelinids, in themonocots. The family then consisted ofone genus (Typha), totalling a dozen species ofperennial plants of wet habitats. More recently, theAPG III system of 2009 included a second genus,Sparganium, in this family. The two genera together have a total of 51 known species.[5]
