Oreocharis guileana (B.L. Burtt) Li.H.Yang & F.Wen, 2020

Yang, Li-Hua, Wen, Fang, Kong, Hang-Hui, Sun, Zhi-Xia, Su, Lan-Ying & Kang, Ming, 2020, Two new combinations in Oreocharis (Gesneriaceae) based on morphological, molecular and cytological evidence, PhytoKeys 157, pp. 43-58 : 43

Oreocharis guileana (B.L. Burtt) Li.H.Yang & F.Wen comb. nov. Figure 1A-H

≡ Boeica guileana B.L. Burtt (1977: 371).

Type.

China. Hong Kong: New territories, Ma On Shan, 690 m alt., ravine in montane forest, on rocks in humid shade, July 1974, Guile; culture in R.B.G. Edinb. 1976, C.8467 (holotype: E!).

Amended description.

Perennial herbs with inconspicuous rhizome. Leaves in basal rosette, 8-22; petiole 1-3 cm long, with densely white villous; leaf blade elliptic to ovate or obovate, 2-6 × 1.1-3.2 cm, white villous and pubescent on both sides, abaxially more densely villous along veins, base cuneate, margin serrate, apex acute to rounded; lateral veins 4-6 on each side of midrib. Cymes 1-5, axillary, 1-4-flowered. Peduncles 2.5-5.5 cm long, with brown villous; bracts 2, lanceolate, 2.5-3 × ca. 1 mm, margins entire, outside brown villous; pedicel 1-2 cm long, with brown villous. Calyx 5-lobed near base, lobes equal, lanceolate to linear, 3-5 × ca. 1 mm, outside covered by brown villous, margin entire. Corolla blue-purple, outside with sparely-brown villous; tube short and not swollen, 1.5-2.5 mm long; adaxial lip 2-lobed near base, lobes obovate-oblong, margin entire or slightly erose, apex obtuse, 5-7 × 4-5 mm; abaxial lip 3-lobed near base, lobes obovate-oblong, margin entire or slightly erose, apex obtuse, 9-12 × 4.5-6 mm. Stamens 4, adnate to corolla base, filaments linear, with sparsely pubescent, adaxial stamens ca. 3 mm long, abaxial stamens ca. 4 mm long, anthers dorsifixed, free, ovate-oblong, dehiscing longitudinally, glabrescent; staminode absent; disc not obvious; pistil 8-12 mm long; ovary conical, 2-3.5 mm, with densely-white villous; style 6-8 mm long, with pubescent. Stigma 1, disc-shaped. Capsule ca. 1.5 cm long, villous, dehiscing loculicidally to base, initially on one side, valves 2, capsule straight in relation to pedicel, not twisted.

Distribution and habitat.

Oreocharis guileana was once recognised as an endemic species and only recorded at Ma On Shan, Hong Kong. However, recent field works reveal that it can be found from several sites in Shenzhen, such as Wu Tong Shan, Pai Ya Shan, Tian Xin Shan, Dakeng reservoir and Xigong village (Fig. 5 ). The plants grow on moist rock surfaces under evergreen broad-leaved forests, at an altitude of 300-900 m.

Note.

Burtt (1977) thought that Oreocharis guileana is morphologically similar to Boe. brachyandra and Boe. nutans by its rosette habit, short corolla tube and spreading limb. However, as mentioned above, the currently taxonomic status of these two Boeica species is doubtful and need further studies to confirm it. Additionally, the distinctively disjunctive distribution between Oreocharis guileana and Boe. brachyandra and Boe. nutans may indicate a distant relationship between them ( Oreocharis guileana is a species occurring in S China, but Boe. brachyandra and Boe. nutans are distributed on the Malayan Peninsula). Although with low support, our phylogenetic results show that Oreocharis guileana and O. pilosopetiolata have a sister relationship (Fig. 3 ). These two species have similar leaf blade (size, shape, texture and margin) and indumentum on most of organs and it is difficult to distinguish these two species without flowers. Additionally, the related adjacent geographic distribution also indicates the close relationship between these two species (Fig. 5 ).

Additional specimens examined.

China. Shenzhen Special Economic Zone, Pingshan District, Tian Xin Shan, alt. 300 m, 22 May 2017, 114°25'E, 22°41'N, L.H. Yang & F. Wen YLH383 (IBSC!); in the same place, alt. 300 m, 20 October 2005, S.Z. Zhang et al. 4658 (SZG!); 20 April 2005, S.Z. Zhang et al. 0384 (SZG!); 5 November 2004, S.Z. Zhang et al. SCAUF490 (SZG!), SCAUF491 (SZG!), SCAUF583 (SZG!); Longgang District, Pai Ya Shan, alt. 600 m, 25 October 2006, G.D. Wang et al. 6896 (SZG!); 13 October 2005, S.Z. Zhang et al. 4533 (SZG!); 17 December 2005, S.Z. Zhang et al. 2144 (SZG!); 8 June 2005, S.Z. Zhang et al. 2340 (SZG!); Xi Chong, Xigong village, 8 November 2004, S.Z. Zhang et al. SCAUF469 (SZG!), SCAUF470 (SZG!); Luohu District, Wu Tong Shan, alt. 900 m, 7 October 2005, S.Z. Zhang et al. 4288 (SZG!); 23 March 2005, Team of Flora of Shenzhen 013556 (SZG!); Longgang District, Dakeng reservoir, 16 July 2005, S.Z. Zhang et al. 2932 (SZG!).

Figures

Figure 1. Photographs of Oreocharis guileana (A-H), O. pilosopetiolata (I), Boeica ferruginea (J) and Beccarinda tonkinensis (K). A, E, I habit B, C flower D opened corolla, showing stamens and staminodes F pistil G, H, J, K mature fruit.

Figure 3. Bayesian (> 50 %) tree resulting of the combined nuclear (ITS) and plastid (trnL-F) data matrices. Posterior probability (PP) from the BI analysis are indicated above branches and Bootstrap value (BS) from the ML analysis are indicated below. The asterisk indicates a BS <50. The dash indicates the topological discordance between ML and Bayesian tree. The two species, O. baolianis and O. guileana, are highlighted in bold.

Figure 5. Geographical distribution of Oreocharis guileana (green dot), O. baolianis (red triangle) and O. pilosopetiolata (blue square).