Embryo with 1 or 2 cotyledons. Sieve tubes with companion cells. Plants annual or perennial; terrestrial or aquatic; woody or herbaceous. Leaves simple, compound, reduced to scales or absent. Roots present, ± well developed. Flowers unisexual or bisexual; aggregated into inflorescences or solitary; usually 3—5-merous. Ovules enclosed within carpels bearing ± well developed styles and stigmas. Carpels solitary, free from each or connate within the flower. Stamens with 2 lateral theceae; male gametophyte 3-celled.To count the loculi in an ovary, cut a transverse section of the ovary and then lightly squeeze the bottom half. The ovules should then pop out and they can be brushed away with the finger and the loculi exposed.