or dioecious herbs or shrubs with stinging
hairs. Leaves simple, alternate, petiolate; stipules
deciduous, intrapetiolar; leaf blade papery, pinnately veined or 3-veined,
margin dentate or serrate, rarely entire; cystoliths punctiform.
Inflorescence axillary, solitary, loose
glomerules forming panicles or racemes or spikes, pedunculate, unisexual; bracts very small. Flowers in loose
glomerules. Male flowers: perianth lobes
4 or 5, free;
stamens 4 or 5, filaments reflexed; rudimentary ovary clavate. Female flowers: perianth lobes 4, free
or connate, unequal; staminodes absent;
ovary superior; styles filiform, rarely brush-like. Fruit an achene,
compressed, ovoid to hemispherical. Seeds with
thin or no endosperm.