DENDROCNIDE LATIFOLIA (GAUD.) CHEW

The Urticaceae Juss. or nettles is a family of dicot angiosperms comprised of over 2600 species arrayed in 59 genera (POWO 2023) and distributed globally, excepting polar regions. Many present urticating or stinging hairs on their leaves, stems, or inflorescences. One genus, the tropical to subtropical Asian Dendrocnide Miq., consists of about 36 species (POWO 2023) and includes D. latifolia, which is found on islands of the tropical western Pacific, including the Mariana Archipelago.

Growing to a small tree, D. latifolia can be found on four of the five southernmost islands of the Marianas, Guam, Rota, Saipan, and Tinian (Fosberg et al. 1979), where it inhabits primary and secondary limestone forests, tolerating open canopy and poor soils, such as cliff edges and heavily karstic terrain. Some authors (e.g., Kanehira 1931, Stone 1970, Vogt & Williams 2004) have considered the tree less common on the southernmost island of Guam. The plant is often encountered as a tall shrub with irregular sinuous branching (Fig. 1A). However, the species is most easily identified by its large (to 20 cm in length), lanceolate to elliptic and glabrous leaves with entire margins and about a dozen pairs of impressed, evenly spaced curving lateral veins and a long (to 10 cm) petiole with which the leaves are arrayed in terminal whorls atop smooth, grey, and terete branches bearing prominent abscission scars (Fig. 1B). Inflorescences are unisexual, axillary, and in dense racemes of green florets, the pistillate form (Fig. 1C) wielding the family's characteristic irritating hairs (Chew 1969), even when dropped and decomposing (Vogt & Williams 2004), the staminate flowers appearing differently (Fig. 1D). The fruits are fleshy, greenish white, and drooping. Seedlings also present urticating hairs (M. Martinez 2023, pers. comm.).

Dendrocnide latifolia was originally described by Charles Gaudichaud-Beaupré (1844) from specimens he collected in Vanuatu in 1837 during his second circumglobal voyage, aboard the Bonite, Auguste-Nicolas Vaillant commanding. However, the botanist may have collected D. latifolia and conceivably recorded its Chamoru name in the Marianas in 1819 during his extended visit there of 12 weeks while aboard the Uranie, Louis Claude de Saulces de Freycinet commanding. During this time, he explored three of the islands inhabited by the species (L. Freycinet 1829: 155). Unfortunately, their ship later struck a submerged reef in the Falkland Islands (R. Freycinet 1927: 127, Rivière 2003: 125) and about a third of his specimens were lost (Bauchot et al. 1990: 36). However, in his summary notes of the expedition transcribed upon his return to France (Wamprechts 2011), Gaudichaud does not list among his 17 specimens of Urticeae (= Urticaceae) collected in the Marianas exemplars of Laportea, the genus he erected (Gaudichaud 1826: 498) to accommodate his new Vanuatuan species L. latifolia, later transferred to Dendrocnide by Chew (1965).