Lanonia verrucosa Henderson & Nguyen Quoc Dung, 2017

Henderson, Andrew & Dung, Nguyen Quoc, 2017, New species of Lanonia, Licuala, and Pinanga (Arecaceae) from Vietnam, Phytotaxa 323 (2), pp. 159-172 : 163

Lanonia verrucosa Henderson & Nguyen Quoc Dung sp. nov. ( Fig. 4 )

Type:— VIETNAM. Khanh Hoa Province: Ninh Hoa District, Ninh Tay Commune, road to hydroelectric dam, 12°35’N 108°58’E, 433 m, 7 October 2016, A. Henderson & Nguyen Quoc Dung 4079 (holotype VFM!, isotype NY!).

It differs from similar species with few (3–13) segments and the central segment much wider than the others ( L. calciphila , L. dasyantha , L. magalonii ) in its exceptionally wide central segment and distantly spaced, warty fruits.

Stems solitary, 1.5 m tall, 6.0 cm diameter. Leaf number not recorded; sheaths not recorded; ligules not recorded; petioles 130.0 cm long, thorny along the margins; blades to 80.0 cm across, split into 6–8, unequal segments; costa 15.5 cm long; central segment split into 2 lobes, these 45.0 cm long, 18.0 cm wide at the apex; lateral segment 36.0 cm long, 11.5 cm wide at apex; segments briefly indented at the apex. Inflorescences erect amongst the petioles; staminate inflorescences branched to 1 order; prophylls not recorded; peduncles to 10.0 cm long; partial inflorescence 1; rachillae to 12.0 cm long, minutely hairy; staminate flowers 3.0 mm long, solitary or in clusters of 2–3; calyx 2.0 mm long, tubular at the base for ca. 1.0 mm, cupular and shallowly lobed above; corolla 3.0 mm long, split for ca. half its length into 3, valvate petals; stamens 6; filaments with scarcely developed staminal ring, unequal with 2 longer than the other 4; pistillode 3-parted; pistillate inflorescences larger than the staminate, branched to 2 orders; prophylls 30.0 cm long; peduncles to 60.0 cm long with 1, narrow, tubular, glabrous peduncular bract; partial inflorescence 1; rachillae 9.5–16.5 cm long, minutely hairy; pistillate flowers not seen at anthesis, solitary; calyx tubular at the base, 3- lobed above, each lobe splitting again as the fruits develop to give a 6-lobed calyx; corolla with 3 petals, these reflexed as fruits develop; fruits ellipsoid, 1.1 cm long, 0.7 cm diameter, orange, the surface warty; endosperm homogeneous.

Distribution and habitat:—Southern Vietnam in Khanh Hoa province in disturbed forest on steep, rocky slopes at 433 m elevation.

Taxonomic notes:— Lanonia verrucosa most resembles L. dasyantha , although this occurs almost 900 km to the north. It differs from L. dasyantha in its non-mottled leaves (versus mottled), erect inflorescences (versus curving down below the leaves), and wiry flowering braches (versus thick and fleshy). Flowers are distantly spaced along the flowering branches, as opposed to the arrangement in L. dasyantha in which they are closely spaced and the fruits are consequently closely packed in the infructescence.

Figures

FIGURE 4. Lanonia verrucosa. Left, leaf blade with wide central segment lobes. Right, infructescence with warty fruits (from Henderson & Nguyen Quoc Dung 4079).