Oreocharis jasminina S.J.Ling, F.Wen & M.X. Ren, 2020

Ling, Shao-Jun, Guan, Shu-Ping, Wen, Fang, Shui, Yu-Min & Ren, Ming-Xun, 2020, Oreocharis jasminina (Gesneriaceae), a new species from mountain tops of Hainan Island, South China, PhytoKeys 157, pp. 121-135 : 121

Oreocharis jasminina S.J.Ling, F.Wen & M.X. Ren sp.nov. Figs 2 , 3

Diagnosis.

Oreocharis jasminina has the closest phylogenetic relationship with O. dasyantha , O. dasyantha var. ferruginosa and O. flavida with very high support values, all being Hainan-endemic and monophyletic. O. jasminina can be easily distinguished from them by having: (1) a long and narrow floral tube (both O. dasyantha and O. dasyantha var. ferruginosa have conical floral tubes, O. flavida has campanulate-tubular floral tube); (2) yellow and actinomorphic corolla (both O. dasyantha and O. dasyantha var. ferruginosa are zygomorphic with orange-red to yellow corolla, O. flavida is actinomorphic with orange corolla); (3) didynamous stamens with ovate anthers hidden in the floral tube (both O. dasyantha and O. dasyantha var. ferruginosa have exposed didynamous stamens with ovate anthers, O. flavida has four equivalent stamens with horseshoe-shaped anthers included in the floral tube) (Table 1 , Fig. 4 ).

Type.

China. Hainan: Qiongzhong County (琼中县), Limu Mountain, 1350 m a.s.l., on moist rocks, 26 Nov 2018, S.J.Ling 2018112601 (holotype: HUTB!; Isotypes: HUTB!, KUN!).

Description.

Perennial herb, rhizomatous, leaves basal; 4.0-10.0 cm long, 2-3 mm in diameter, densely pale brown villous or woolly; leaf blade ovate to broadly ovate, rarely elliptic or obovate, 6-11 × 4-8 cm, adaxially densely grey to brown pubescent, abaxially sparsely to densely grey or grey-brown pubescent, sparsely brown villous along veins which are adaxially sunken and abaxially ridged, lateral veins 6-7 on each side of midrib, base often cordate to rounded, margin nearly entire to shallowly crenate, apex rounded. Cymes axillary, 2-3, inflorescence 3-10-flowered; Peduncle 9-16 cm long, sparsely pale grey villous; bracts 2, linear to narrowly triangular, outside densely villous, apex acuminate, cuneate to triangular, margin entire; pedicel 1.5-2.2 cm long, densely pale brown villous to woolly. Calyx 5-lobed, divided to base, lobes green, narrowly lanceolate, 9-11 × ca. 2 mm, apex acuminate, margin entire, outside villous, inside glabrous. Corolla yellow, 1.7-2.2 cm long, outside pubescent; tube thin tubular, 1.8-2.1 cm × 3-4.5 mm, limb barely 2-lipped, adaxial lip shallowly 2-lobed from near base, abaxial 3-lobed slightly equal. Stamens 4, 8-9 mm long, included, adnate to corolla 4-5 mm from base; filaments slender, pubescent; anthers ovate, 2-loculed, dehiscing transversely; staminode 1, adnate to corolla 2-4 mm from base, ca. 2 mm. Disc ca. 1 mm high, entire. Pistil ca. 7 mm long; ovary cylindrical, ca. 5 mm long, glabrous. Stigma 2, equal, suborbicular. Capsula linear, 3-4 cm long, glabrous to sparsely puberulent.

Phenology.

Oreocharis jasminina flowers from September to December and fruits from November to January.

Distribution and habitat.

Oreocharis jasminina is currently only found in cloud forests on the mountain tops of Mt. Limu and Mt. Yingge, in the middle of Hainan Island. The habitat of O. jasminina is on the moss layer on wet rocks under cloud forests.

Etymology.

The specific epithet refers to the yellow and narrowly tubular corolla of this new species.

Vernacular name.

迎春花马铃苣苔 ( Yíng Chūn Huā Mǎ Líng Jù Tái) is the Chinese name for Oreocharis jasminina , the first three characters meaning 'winter jasmine’, indicating its similar floral syndromes to Jasminum nudiflorum Lindl. The last four characters are the Chinese name for Oreocharis .

Conservation status.

Oreocharis jasminina is, so far, known only from the two locations with about 800-1000 individuals. The populations are under threat due to the restricted and fragmented habitat. Therefore, we propose that O. jasminina should be considered as ‘Vulnerable’ (VU), according to the IUCN Red List Categories and Criteria ( IUCN 2012).

Figures

Figure 2. Oreocharis jasminina sp. nov. A Habitat B habit C face view of corolla D lateral view of corolla E opening flower showing stamens and staminode F stamens and staminode G pistil and sepals H fruit pods I adaxial leaf surface J abaxial leaf surface.

Figure 3. Oreocharis jasminina sp. nov. (all drawings based on the holotype S. J. Ling 20181126 - 01 in HUTB, drawn by S. P. Guan). A Habit B face view of corolla C lateral view of corolla D opening corolla showing pistil and stamens E pistil F stamens and staminode.

Figure 4. Three formerly-recognised Oreocharis taxa in Hainan Island. Oreocharis dasyantha (A, B), Oreocharis dasyantha var. ferruginosa (C, D) and Oreocharis flavida (E, F).