Also found in: Dictionary, Thesaurus, Wikipedia.
a family of monocotyledonous plants; it includes the single species Najas. The diclinous, small, inconspicuous flowers are solitary or, less frequently, in groups of two or four; they are borne on an extremely reduced axial shoot and are usually enclosed in a small membranous spathe. In pistillate flowers the spathe is often absent or sometimes fused to the ovary. The staminate flowers have one stamen, which is equipped with an almost sessile anther; the pistillate flowers have two to four stigmal branches. The Najadaceae are either monoecious or dioecious; blossoming and fertilization occur underwater. The fruit is indehiscent and monospermous.