Oreocharis brachypodus J. M. Li &Z. M. Li, 2015

Li, Jia-Mei & Li, Zhi-Ming, 2015, Oreocharis brachypodus (Gesneriaceae), a new taxon from Guizhou, China, Phytotaxa 204 (4), pp. 296-299 : 296-298

Oreocharis brachypodus is most similar to Oreocharis villosa ( Pan 1986: 31–33) Möller & Weber (2011: 27) which shares sessile or shorter petiole (up to 2 mm long) and leaf blade obovate ( Figs.1–3 ). However, the new species is readily distinguished by cymes not branched, 1–4-flowered, larger and pronounced gibbous corolla (2.2–2.5 cm), anther thecae confluent, and ovary ca. 1 cm long, with 4 ribs prominent, style ca. 0.7cm long.

Oreocharis brachypodus J. M. Li &Z. M. Li , sp. nov. ( Fig. 1 A–G & Fig. 2 A–F )

Type: ― CHINA. Guizhou: in the vicinity of Tongren city, on rather cool rocks and very steep banks of cool clammy soil that grows a fine film of moss, alt. 1300m, 9 April 2014, Jia-Mei Li 2304 (holotype HEAC!) ; ibid. Jia-Mei Li 2305 (paratype HEAC!) .

Rosulate herbs, perennial, stemless. Rhizome 2–3 mm, vertical, woody, with many long fibrous roots. Leaves clustered at the apex of the rhizome; blade obovate, 2–5 × 1.5–3.2 cm, adaxially sparsely brown villous to glabrescent, abaxially rust-brown villous, brown villous especially on the veins and round the margins, apex rounded, base broadly cuneate, margin irregularly dentate in apical half; lateral veins 3 or 4 on each side of midrib, adaxially indistinct, abaxially protuberant; petiole 0–2mm long. Inflorescences axillary with pair-flowered cymes, not branched, 1–6 on each plant, each 1–4-flowered, peduncle 4–6.5 cm long, with subglabrous on the higher to rust-brown hairs on the lower; bracts 2(or 3), entire, ca. 3 mm long, brownish villous. Pedicel 2–3 cm long, subglabrous to brown villous. Calyx 5-sect from base; segments equal, narrowly triangular, 3mm long, margin entire, hairy only at the apex. Corolla white to light purple, 2.2–2.5 cm long, outside and inside glabrous; corolla limb distinctly 2-lipped; adaxial and adaxial lobes equal, oblong, spreading, longer up to 0.8 cm; adaxial lobes 2-sect, divided to above middle, abaxial lobes 3-sect; corolla tube narrowly urceolate, sometimes ampliate basally, contracted at the throat, 15 (–18) × ca. 3.5 mm, 2–3 × longer than limb. Stamens 4, 6–8 mm long, adnate to corolla 9 mm above base, included; filaments glabrous; anthers coherent in pairs, anther thecae horseshoe-shaped, divergent at base, confluent at apex; staminode 1, ca. 3.5 mm long, adnate to adaxial side of corolla tube. Pistil ca. 17 mm long, glabrous; disc ringlike, many-lobed or entire; ovary 1 cm long, with 4 ribs prominent. Stigma 1, truncate, emarginated. Capsule straight, blanceolate-oblong. Flowering March–April, fruiting April–May.

Distribution, Ecology, Phenology and Conservation status:— The new species is rare and localized, and seems to occur only in Jiulong Cave, close to Tongren city. The plant thrives in rock fissures or on thin soil with direct contact with the serpentine rock. It was collected in flower and fruit in March–May. Its populations are small, each consisting of up to 40 individuals and growing in an area of a few square metres.Around 500 mature specimens of the new species were observed in an area of occupancy of less than 500m 2. The populations are highly vulnerable to anthropogenic impact. The area has seen intensive tourist development, and informal grazing and land-use changes, including reforestation, could have a detrimental impact in the future. For this reason, we consider Oreocharis brachypodus to be endangered, and propose that Oreocharis brachypodus should be considered as ‘Critically Endangered’ (CR), CR A1acd, according to IUCN red list criteria (IUCN 2001).

Figures

FIGURE 1 Oreocharis brachypodus. A, habit; B, adaxial and abaxial leaves; C, opened corolla showing stamens and staminodes; D, stamens and pistil before flowering; E, calyx and pedicel; F, calyx and pistil with disc; G. rhizome. Drawn by Dong Hui Xia partially from Fig.2.

FIGURE 3 Oreocharis villosa (photos from the holotype vouchered in PE). A, habit; B, adaxial and abaxial leaves; C, cymes. D, calyx and pistil (left), opened corolla showing stamens and staminodes (right).

FIGURE 2 Oreocharis brachypodus J.M. Li & Z.M.Li sp. nov. A, habit; B, adaxial and abaxial leaves; C, opened corolla showing two stamens and a pistil with a few ditches before flowering; D, corolla limbs; E, calyx and pistil with disc; F, corolla tube.