Urtica L.
Fls small, greenish, unisexual, in axillary simple or branched spikes or racemes; per. deeply 4-partite; stamens 4, inflexed in bud; ovary us. ovoid; stigma penicillate; ovule 1, erect. Achene us. ovoid; subcompressed, invested by long-persistent per. About 40 spp., mostly temperate and subtropical, of annual to perennial herbs or shrubs, us, bearing stinging hairs; lvs opp., toothed or lobed. The N.Z. spp. are endemic, except U. incisa, which is common in Australia and Tasmania.
Key
2
Plant with very slender, weak, openly branched stems, us. scrambling or lianoid; lvs linear to linear-lanceolate
Plant with stouter simple or branched stems, decumbent to erect, neither scrambling nor lianoid; lvs not linear nor linear-lanceolate