Munronia petiolata N.T.Cuong, D.T.Hoan & Mabb., 2014

Cuong, N. T., Hoan, D. T. & Mabberley, D. J., 2014, Munronia petiolata (Meliaceae), a new species from Vietnam, Blumea 59 (2), pp. 139-141 : 139-141

Munronia petiolata N.T.Cuong, D.T.Hoan & Mabb. , sp. nov. — Fig. 1

Type. N. T. Cuong 301 (holotypus HN; isotypus HN, NY), Vietnam, Quang Ninh province, Ha Long Bay, Bo Hon Island (N20°48'18.6" E107°07'14.1"), 17 July 2014 .

Shrublet 30–60 cm tall. Stem weakly branched; branches pubescent with simple and 3–5-branched stellate hairs to glabrescent. Leaves in spirals, clustered near branch apices, simple; petiole 2–4.5 cm, puberulent; lamina lanceolate or oblong-elliptic, 8.5–17.5 by 2.5–3.3 cm, membranous, abaxially puberulent along midvein and lateral veins, adaxially glabrous or sometimes sparsely pubescent along midvein, lateral veins 6–12 on each side, base cuneate or rounded, margin entire, apex acute, acuminate to caudate. Thyrses subterminal and axillary on apical part of branches, 3–5 cm long, with 3–5 flowers, pubescent; peduncle 1–2 cm long, pedicel 1–1.5 cm long, articulated; bracts linear, 1–2 mm long, accrescent to 5–6 mm in young fruits, pubescent. Calyx pubescent; lobes linear to elliptic, 2–3 mm long, free, apex rotund to weakly acuminate. Corolla white, 2–3 cm long; tube slender, 1.5–2 cm long; lobes obovate, oblanceolate, or elliptic, 12–15 by 5–7 mm, apex acute to rounded. Staminal tube exserted from corolla tube, glabrous; lobes linear, 1.5–2 mm long, apically bifid; anthers elliptic or ovate, 1.5–2 mm long, lanulose with simple hairs, apex acute to mucronate. Ovary subglobose, puberulent; style linear, slightly exserted from staminal tube; stigma 0.5 mm diam. Capsule 1 –1.2 cm diam, depressed globose to pyriform, 4-lobed and -ribbed externally, pubescent; 4 locules, each locule with 1–2 seeds. Seeds yellowish, ovoid, 4–6 mm long, smooth, adaxially concave.

Flowering & Fruiting — June to September.

Distribution & Habitat — Apparently restricted to the islands of Bo Hon, Hang Luon and Cat Lan in Ha Long Bay, Quang Ninh province, Vietnam. It was found growing in crevices of rocks and cliffs on limestone with Dracaena cambodiana Pierre ex Gagnep. , Pterospermum truncatolobatum Gagnep. , Sterculia lanceolata Cav. , Bauhinia ornata Kurz , Glochidion ellipticum Wight , Buxus latistyla Gagnep. , Pistacia weinmaniifolia J.Poiss. ex Franch. and Schefflera alongensis R.Vig.

Conservation status — Munronia petiolata is known only from three limestone islands in Ha Long Bay, North Vietnam, where its distribution covers over 434 km 2. The numbers of plants in the populations and their phenology have so far not been investigated. More research is needed so the species has to be regarded as Not Evaluated ( NE) in the threat categories of IUCN (2012).

Acknowledgement This work was supported by the Vietnam Academy of Science and Technology (code: VAST 04.09/15-16).

Figures

Fig. 1 Munronia petiolata N.T.Cuong, D.T.Hoan & Mabb. a. Branch bearing inflorescences and infructescences; b. detail of apical bud of the shoot; c. detail of leaf; d. stellate hairs in fruit; e. bud; f. corolla lobes and staminal tube; g. detail of androecium apex with style; h. ovary and style; i. capsule; j. seed (dorsal); k. seed (ventral) (all: N.T. Cuong 302, HN). — Scale bars: a = 2 cm; b, c, e, i = 1 cm; d = 1 mm; f = 1.5 cm; g = 5 mm; h = 2 mm; j, k = 6 mm. Drawn by L.K. Chi.