Flora of New Zealand Series

Monoec. Infl. of 1 ♂ and several ♀. ♂ of a single stamen; anther 2-celled; pollen spherical. Carpels enclosed in hyaline cup-shaped membrane, shortly stipitate; ovary globose; style short; stigma obliquely peltate. Fr. ± arcuate. Rhizome threadlike, rooting at nodes and giving off long slender branches. Lvs in apparent whorls of 3–4 separated by long internodes; stipules colourless, membr., free from lf-base, sheathing stem, soon deciduous. 1–2 spp. of fresh water, almost worldwide.