Nagyon rejtélyes, a csalánfélék közt nincs ilyen:
URTICACEAE 1. Leaves opposite ................... Pilea
1. Leaves alternate.
2. Inflorescences elongate or branching.
3. Herbs with glabrous stems; style hooked in fruit ....................... Laportea
3. Shrubs with pubescent stems; style none or not hooked.
4. Cystoliths radiate on upper leaf surfaces; stinging hairs none; flowers sessile and clustered along branched spikes; pistillate calyx 0 (ours) but pistil subtended by 2 tiny bracts ...... Gyrotaenia
4. Cystoliths scattered on upper leaf surface; stinging hairs often present; flowers shortly stipitate and clustered at apices of dichotomously branched panicles; pistillate calyx equaling pistil, 4-lobed, accrescent and fleshy in fruit ........ Urera
2. Inflorescence in axillary glomerules. 5. Shrubs; leaves markedly unequal in size at alternate nodes ................... Boehmeria
5. Herbs; leaves k equal at alternate nodes.
6. Leaves entire, ovate to rotund ..... Rousselia
6. Leaves serrate, lanceolate. ........ Phenax