Neo-Uvaria laosensis, 2018

Tagane, Shuichiro, Souladeth, Phetlasy, Zhang, Meng & Yahara, Tetsukazu, 2018, Flora of Nam Kading National Protected Area IV: Two new species of Annonaceae, Monoon namkadingense and Neo-uvaria laosensis, Phytotaxa 336 (1), pp. 82-88 : 85-87

Neo-uvaria laosensis Tagane & Souladeth , sp. nov. ( Fig 2 .)

TYPE:— LAOS. Bolikhamxay Province: Nam Kading National Protected Area, in semi-evergreen forest dominated by Lagerstroemia calyculata Kurz , along logging road, 313 m elev., 18°12’30”N, 104°23’57”E, 24 December 2016, Tagane S., Yahara T., Zhang M., Okabe N., Souladeth P., Sengthong A., Chayer S. L287 [fl. & fr.] (holotype FOF!, isotypes BKF, FU!, HNL! K, KKU, KYO!, P).

Diagnosis. Similar to N. telopea Chaowasku (2011: 32) of Peninsular Thailand in the density of the indumentum, flower shape and large fruit size, but it differs in having fewer secondary veins ((12–)14–17 pairs in N. laosensis vs. 17–18 pairs in N. telopea ), solitary to 5- flowered inflorescences (vs. only solitary in N. telopea ), smaller inner petals (10–11 × 5–5.5 mm vs. 8.5–10 × 7.5–8.5 mm), smaller stamens (1.0– 1.3 mm long vs. 1.6–1.7 mm long) and more carpels (9 vs. 5–8). Also, similar to N. acuminatissima ( Miquel (1865: 6)) Airy Shaw (1939: 279) of Peninsular Malaysia and Borneo, but different in having larger flowers (vs. outer petals ca. 3.6 × 2.5 mm, inner petals ca. 3.8 × 3.0 mm in N. acuminatissima ) and much larger monocarps (vs. 1.7 cm in diam.).

Tree, 11 m tall, 47 cm in dbh, all parts generally covered with stellate hairs intermixed with simple hairs. Young twig ca. 2.5 mm in diam., densely velvet-villous. Petiole 3–5 mm long, 2–3 mm in diam., densely velvety-villous. Leaves elliptic-oblong, (6.5–)11–18.7 × (2–) 4–7 cm, chartaceous, apex acuminate, acumen up to 2.5 cm long, base acute to obtuse, rarely rounded, sparsely hairy adaxially, densely villous abaxially, midrib slightly sunken, velvety adaxially, prominent densely velvety-villous abaxially, secondary veins (12–)14–17 pairs, prominent abaxially, at angle of (40º–)45º–55º from the midrib, tertiary veins scalariforming, faintly visible adaxially, slightly prominent abaxially. Inflorescences axillary or at older leafless nodes, solitary to 5-flowered. Flowers cream, 2–2.5 cm in diam., bracts triangular to suborbicular, to 3 mm long, densely covered with golden-brown hairs. Sepals ovate-triangular, ca. 6 × 6 mm, connate ca. 0.5 mm from base, densely covered with golden-brown hairs, indumentum on inner side shorter and lighter colored. Outer petals ovate-elliptic, 11–12 × 6–6.5 mm, ±appressed velvety-tomentose abaxially, shortly cobwebbed adaxially except basal ca. 1/5 which is glabrous. Inner petals ovate-rhombic, 10–11 × 5–5.5 mm, shortly cobwebbed on both surfaces except basal ca. 1/5 adaxially. Stamens 18 per flower, 1.0– 1.3 mm long, connective tissue flat-topped, shortly appressed hairy. Carpels 9 per flower, ovaries 1.2 mm long, slightly curved, densely covered with light golden-brown hairs, ovules 1 per ovary, stigmas ellipsoid-cylindrical, 0.5–0.7 mm long, glabrous, apex covered with mucilage. Monocarps 1–3 per fruit, sessile, ellipsoid-ovoid, 6–6.5 cm long, 4–4.5 cm in diam., densely covered by velvety dark brown hairs. Seed 1 per monocarp, ellipsoid, 4.3–4.5 cm long, ca. 3 cm in diam.

Additional specimen examined: — LAOS. Bolikhamxay Province , Nam Kading National Protected Area, 313 m elev., 18°12’09.8”N, 104°23’16.1”E, 25 December 2016, Tagane S., Yahara T., Zhang M., Okabe N., Souladeth P., Sengthong A., Chayer S. L 406 [fl.] (FOF!, FU! (flowers in spirit collection), HNL!, K, KYO!, P) ; ibid., 27 June 2017, Tagane S., Souladeth P., Okabe N., Yang C.-J. L 981 [fr.] (FOF!, FU!) ; 459 m elev., 18°42’37.4”N, 104°11’45.3”E, Tagane S., Souladeth P., Okabe N., Yang C.-J. L1096 [ster.] (FOF!, FU!).

Distribution: — Laos, Bolikhamxay Province (so far known only from Nam Kading National Protected Area).

Habitat and Ecology: — Neo-uvaria laosensis is scattered in evergreen forests, also on limestone, at 260–460 m elevation. The forest the above type specimen collected is dominated by Dipterocarpus grandiflorus ( Blanco, 1837: 451) Blanco (1845: 315) and Lagerstroemia calyculata Kurz (1872: 307) .

Phenology: —Flowering specimens were collected in December; fruiting in July and December.

DNA barcodes: —GenBank accession no. LC317011 (rbcL), LC317012 (matK); we sequenced Tagane et al. L287. The BLAST similarity search based on the rbcL sequence of N. laosensis resulted in homology as high as 510/511 bp with the sequence of Neo-uvaria acuminatissima (AY318999) and also Neo-uvaria teropea (KY988309) in the DNA database. The matK sequence of N. laosensis differs 2 bp of the total 755 bp from Neo-uvaria acuminatissima (AY518793) and 3 bp of the total 758 bp from Neo-uvaria telopea (JX544751).

Etymology: —The specific epithet refers to the country where the new species is known to occur.

Vernacular name:—ກະແຊງດງນາກະດງ (Ka Xaeng Dong Nam Kading, suggested here).

Primary conservation assessment: —Endangered (EN). Neo-uvaria laosensis is widely scattered in Nam Kading National Protected Areas as in Monoon namkadingense , and often the two species occur sympatrically. For the same reason to M. namkadingense (B1a & b), the IUCN category of this species is proposed as EN.

Note: —The genus Neo-uvaria is a small genus consisting of 9–15 species in the family Annonaceae and all the previously known species are distributed in Malesia region (southern Thailand, Peninsular Malaysia, Borneo, Sumatra and the Philippines) ( Chaowasku et al. 2011). Our discovery documents for the first time the occurrence of Neo-uvaria outside Malesia, representing the northern limit of its distribution range.

Figures

FIGURE 2. Neo-uvaria laosensis Tagane & Souladeth.A) Fruiting twig, B) Top branch and portion of lower leaf surface, C) Flower buds, D & E) Flowers, F) Flower one inner petal and some stamens removed, G) Outer petals, H) Inner petals, I) Stamens, J) Carpels. Materials F–J from Tagane et al. L426 (FU). Scale bars F–H = 5 mm; I & J = 1 mm.