Dendrocnide is a genus of approximately 40 species of evergreen shrubs and trees in the nettle family Urticaceae, order Rosales. Native across North East India, Southeast Asia, Australia, and the Pacific Islands, they are commonly known in Australia as stinging trees — a name earned by the fine, needle-like stinging hairs that cover their stems, leaves, and fruits.
Plants in the genus are characterised by a sympodial growth habit and soft, fast-growing wood. Most species are relatively modest in stature, filling the role of pioneer plants in areas of disturbed rainforest. A notable exception is the giant stinging tree (D. excelsa), which can reach 35 metres in height. Leaves are simple, alternate, and petiolate, with blades that may be entire or dentate; they are often large and either leathery or papery. The stipules are fused and deciduous, leaving conspicuous scars on the twigs. Inflorescences are axillary; most species are dioecious, with male flowers 4- or 5-merous and female flowers 4-merous. The fruit is a small achene, often compressed and sometimes enclosed in a swollen pedicel.
The genus was established in 1851 by the Dutch botanist Friedrich Anton Wilhelm Miquel, who described it in his work Plantae Junghuhnianae based on specimens from the Dutch East Indies. He named it from the Ancient Greek déndron (tree) and knī́dē (nettle), reflecting the tree-like proportions of many of its species. Dendrocnide contains around 41 species recognised by current authorities, distributed from the foothills of the Himalayas through Southeast Asia to Australia and scattered Pacific island groups.
Etymology
The name Dendrocnide derives from the Ancient Greek déndron (tree) and knī́dē (nettle), alluding to the tree-like stature that distinguishes these plants from the smaller, herbaceous nettles of related genera.
Distribution
Dendrocnide species are distributed across North East India, Southeast Asia (including Malesia and the Philippines), Australia (principally Queensland and New South Wales), and numerous Pacific island groups including Melanesia, Micronesia, and Polynesia. Individual species show more restricted ranges: D. excelsa and D. moroides are largely confined to eastern Australia, while many species are endemic to New Guinea, the Philippines, or Sulawesi.
Ecology
Most Dendrocnide species are fast-growing pioneer plants that colonise gaps and margins in tropical and subtropical rainforest, particularly on disturbed ground. Their stinging hairs serve as a strong deterrent to browsing herbivores. The stinging reaction is caused by monosilicic acid and possibly bioactive peptides embedded in the hollow silica needles, which break off on contact and inject their contents into the skin.
Taxonomy Notes
The genus was raised by Friedrich Anton Wilhelm Miquel in 1851 and published in Plantae Junghuhnianae (p. 29), describing three original species: D. peltata, D. costata (now treated as D. stimulans, the original type species), and D. coerulea. GBIF backbone authorship is cited as Miq. The most recent circumscription by Plants of the World Online recognises 41 species. Dendrocnide belongs to the tribe Urticeae within Urticaceae.
