Lanonia verrucosa Henderson & Nguy

Henderson, Andrew & D ựng, Nguy ễn Qu ốc, 2022, A revision of Lanonia (Arecaceae, Coryphoideae, Livistoninae), Phytotaxa 532 (3), pp. 209-245 : 241

19. Lanonia verrucosa Henderson & Nguy ễn Quốc Dựng (2017: 163). 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 & Nguyễn Qu ốc Dựng 4079 (holotype VFM!, isotype NY!) .

Stems 1.5 m long, 6.0 cm diameter,solitary. Leaves number not recorded; ligules not recorded;sheaths and proximalmost part of petioles with scattered, brown scales; petioles 130.0 cm long, 0.8 cm wide at the apex; petiole thorns usually poorly developed, brown or black, more or less regularly arranged on proximalmost part of petiole; hastulas raised, triangular, infolded; leaf blades 80.0 cm wide; costas 17.0 cm long, narrow, with a pulvinus at the apex abaxially, with the few segments free except the middle pair joined at their bases; segments 7 per leaf, not mottled, with minute, reddish-brown scales abaxially, with (on dried specimens) straight margins; middle segments 43.0 cm long, 18.0 cm wide at the apex; apices of middle segments with adaxial splits not much deeper than abaxial ones. Inflorescences length not recorded; prophylls and peduncles length not recorded; rachis bracts flattened, splitting apically and laterally, usually densely brown tomentose; rachillae not filiform nor thick and ribbed, sparsely to moderately covered with short, mostly simple, brownish hairs; staminate inflorescences rachises, number of partial inflorescences, branching, and number of rachillae not recorded; staminate rachillae 11.5 cm long, 0.9 mm diameter; staminate flowers 3.0 mm long; sepals pedicellate at the base, not densely hairy; petals rounded at the apex; stamens with equal filaments and longer, rectangular anthers; filaments not elongate; pistillodes undivided; pistillate rachises absent; pistillate partial inflorescences 1, branched to 3 orders; pistillate rachillae on proximalmost partial inflorescence 11, 16.5 cm long, 1.6 mm diameter; pistillate flowers length and styles not recorded; fruits 8.9 mm long, 7.2 mm diameter, ellipsoid, orange, with uneven, ridged surfaces; seeds with a curved basal intrusion.

Distribution and habitat:—Southern Vietnam in Khanh Hoa province in disturbed forest on steep, rocky slopes at 433 m elevation ( Fig. 17 ).

Taxonomic notes:— Specimens determined as preliminary species Lanonia verrucosa share a unique combination of qualitative variable states and are therefore recognized as a phylogenetic species.

Lanonia verrucosa appears similar to L. acaulis and L. dasyantha , sharing with those species ellipsoid fruits with uneven, ridged surfaces. It differs from these species in its non–mottled (versus mottled) leaves, slender (versus thick and ribbed) rachillae, pedicellate (versus non-pedicellate) staminate sepals, and staminate petals with rounded (versus narrowed) apices.

Figures

FIGURE 17. Distribution maps of L. nuichuaensis, L. poilanei, L. tenuisecta, and L. verrucosa.