Licuala lamdongensis 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 : 167

Licuala lamdongensis Henderson & Nguyen Quoc Dung sp. nov. ( Fig. 8 )

Type:— VIETNAM. Lam Dong Province, road northwest from Bao Loc to beyond Alumina factory, 11°45’N 107°48’E, 16 October 2016, A. Henderson & Nguyen Quoc Dung 4159 (holotype VFM!, isotype NY!).

It differs from similar species ( Licuala honheoensis , L. parvula , L. robinsoniana ) with inflorescences branched to 2 orders, tubular rachis bracts, and flowers borne on raised pedicels, by its zigzag rachillae, long (5.0– 5.5 mm) flowers, and non-hairy corollas.

Stems solitary or clustered, 1.0–2.0 m tall, 4.0 cm diameter. Leaf number not recorded; sheaths and ligules not recorded; petioles 1.0 m long, thorny on ca. proximal half; blades split into 12–22 segments, these with straight or slightly curved sides; costa continuous into central segment, forming a petiolule; middle segment 49.5–55.4 cm long, 3.8–5.7 cm wide at apex; lateral segment 43.5–44.0 cm long, 0.7–1.1 cm wide at apex; segments briefly indented at the apex, with minute, brown scales abaxially. Inflorescences erect, projecting above the leaves, branched to 2 orders; prophylls not recorded; rachis bracts to 22.5 cm long, tubular, fraying at the apices; rachillae 4.0– 13.5 cm long, zigzag, densely covered with short, light brown hairs; flowers 5.0– 5.5 mm long, paired on a raised pedicel, the pairs approximately regularly arranged; calyx 3.0 mm long, densely hairy as the rachillae, tubular at the base, cupular above, scarcely lobed at the apex; corolla 5 mm long, split for ca. two thirds its length into 3, valvate petals, these brown tomentose at the apex; staminal ring ca 0.5 mm long; pistil 3.5 mm long; fruits not seen.

Distribution and habitat:— Lam Dong and Binh Thuan provinces in lowland rainforest at 600–987 m elevation.

Taxonomic notes:— Two of the specimens examined (Poilane 78, 21006) were cited by Gagnepain as L. bracteata Gagnepain (1937: 153) , but we consider they belong here. The only specimen from Binh Thuan province has much less obviously zigzag rachillae but is otherwise similar to other specimens.

Additional specimens examined. VIETNAM. Annam: Blao, kil. 19 de la route col. No. 20 près du Haut Donnai, 900 m, 27 September 1932, Poilane 21006 ( P) ; Annam: Station Agricole de Blao près du Haut Donnai, 800 m, 16 April 1933, Poilane 78 ( P) ; Lam Dong: Bao Lam district, Loc Bao municipality, 7 km NNW from Loc Bao town, 11°50’10”N, 107°38’10”E, 600 m, 26 April 2012, Nuraliev 628 ( NY). Binh Thuan: Bac Binh District , Phan Son Commune, road between Luong Son and Di Linh, Ka Long Song Mao Nature Reserve, 11.50N, 108.35E, 987 m, 23 October 2009, Henderson et al. 3635 ( HN, NY) .

Figures

FIGURE 8. Licuala lamdongensis. Left, habit. Right, densely hairy rachilla and flower buds (from Nuraliev 628, images by Dr. Maxim Nuraliev).