Electronic Flora of South Australia Family Fact Sheet
Phylum Magnoliophyta – Subphylum Seagrasses – Class Liliopsida – Subclass Alismatidae – Order Hydrocharitales
Monoecious or dioecious; annual or perennial aquatic herbs. Leaves basal or arising along the stem, eligulate. Squamules present in each leaf axil. Tannin cells present or absent. Flowers actinomorphic, unisexual, trimerous, sessile or pedicellate, enclosed in a spathe of 2 bracts, free or fused together. Perianth in one or two whorls of 3 free segments. Male flower with anthers sessile or with slender filaments, bi- or quadrilocular, longitudinally dehiscent. Pollen grains globose to ellipsoid, frequently united by mucilage into moniliform chains; pollination hydrophilous. Female flower frequently with the perianth borne on a slender hypanthium; ovary inferior, compound (by loose union of the carpels), unilocular, placentation parietal. Fruit usually indehiscent.
Taxonomic notes: A diverse family of cosmopolitan distribution with about 15 genera, both freshwater and marine, with one marine genus in southern Australia.
References: The Marine Benthic Flora of Southern Australia Part I
Womersley, H.B.S. (31 May, 1984)
The Marine Benthic Flora of Southern Australia
©Board of the Botanic Gardens and State Herbarium, Government of South Australia
State Herbarium of South Australia