Description from Flora of China
Hyrtanandra Miquel; Memorialis Buchanan-Hamilton.
Herbs perennial or subshrubs, sometimes diffuse, without stinging hairs. Leaves opposite or sometimes alternate in upper stems; stipules often persistent, lateral, intrapetiolar, free; leaf blade 3(-5)-veined, margin entire; cystoliths punctiform. Inflorescences axillary, glomerules of male and female flowers or unisexual (plants monoecious or dioecious); bracts small, membranous. Male flowers subglobose, apex abruptly truncate; perianth (3 or)4 or 5, usually free, valvate, segments angled, transversely crested or villous; stamens as many as perianth lobes; filaments inflexed in bud; rudimentary ovary present. Female flowers: perianth tubular, often ovoid and beaked, constricted and 2-4-toothed at apex; staminodes absent. Ovary included; style present; stigma filiform, villous along 1 side, deciduous with style; ovule orthotropous. Achene enclosed by marcescent, always accrescent, and often longitudinally winged or ribbed perianth; pericarp often crustaceous, lustrous. 2n = 26.
Some authorities include Gonostegia within Pouzolzia.
About three species: tropics and subtropics of Asia and Australia; three species in China.
(Authors: Chen Jiarui (陈家瑞 Chen Chia-jui); Ib Friis, C. Melanie Wilmot-Dear)