Oreocharis wuxiensis C.Xiong, F.Chen & F.Wen, 2023

Xiong, Chi, Chen, Feng, Zhang, Jia-Hui, Zhou, Hou-Lin, Zheng, Chang-Bing & Wen, Fang, 2023, Oreocharis wuxiensis (Gesneriaceae), a new lithophilous species from Northeast Chongqing, China, Phytotaxa 594 (1), pp. 73-77 : 74-76

Oreocharis wuxiensis C.Xiong, F.Chen & F.Wen , sp. nov.

( Figs. 1 & 2A 1–G1 )

Diagnosis: — Oreocharis wuxiensis resembles O. giraldii ( Figs. 2A2–G2 ) in foliar and floral characteristics, including the shape and indumentum of the leaf blade, the shape, and color of the corolla. It is easily distinguished by its corolla tube tubular to slightly funnelform and not constricted, lobes semiorbicular or elliptic and as long as 1/3 tube length, staminode absent, pistil glabrous, and ovary as long as the style.

Type: — CHINA. Chongqing: Wuxi County, Sheliangzi, Yintiaoling National Nature Reserve , 31°28′44″N, 109°54′29″E, elev. ca. 1670 m, 24 June 2021, Chi Xiong & Feng Chen YTL21-580 (holotype IBK00445395 !, isotypes IBK00445397 !, CQNM0025460 !) .

Description: —Perennial herbs, rhizomatous, 5–10 mm long. Leaves all basal; petiole 0.5–3 cm long, 2–3 mm in diameter, adaxially pale green, abaxially gray-green, densely rust-brown villous; leaf blade oblong ovate, 2.5–5.5 × 1.5–3 cm, adaxially green, gray pubescent and rust-brown villous, abaxially pale green to gray-green, rust-brown villous especially on the veins, apex acute, base cuneate to broadly cuneate, margin coarsely dentate-serrate; lateral veins usually 3–5, occasionally 6, on each side of midrib, adaxially sunken, abaxially protuberant. Cymes axillary 1–7, inflorescence dichasial, 1–8-flowered; peduncle 5–15 cm long, ca. 1 mm in diameter, rust-brown villous and glandular-pubescent; bracts 2, light green, narrowly triangular to lanceolate, 3–4 × 1–1.2 mm, abaxially rust-brown villous, adaxially glabrous, margin entire; pedicel light green, 0.8–3.2 cm long, ca. 0.5 mm in diameter, glandular-pubescent. Calyx 5-parted to base, lobes equal, lanceolate, 3.5–4 × 0.6–0.8 mm, outside rust-brown villous and glandular-pubescent, glabrous inside. Corolla dark pink to purplish-red, 1.1–1.3 cm long, outside pubescent and glandular-pubescent, inside in the throat and lobes glandular-pubescent, tube tubular from the side view, slightly funnelform in dorsal and ventral views, base slightly inflated, 0.8–1 cm long, 4 mm in diameter at the mouth in dorsal and ventral views; limb 2-lipped; adaxial lip 2-parted to the middle, lobes semiorbicular, 2–3 × 1–2 mm, abaxial lip 3- parted to near the base, lobes elliptic, 3.5–4 × 2–3 mm. Stamens 4, 4.5–5.5 mm long, adnate to corolla ca. 1 mm from base; filaments white, glabrous, straight, curved at apex, anthers coherent in pairs, thecae hippocrepiform, divergent at base, confluent at apex; staminode absent. Disc wax-yellow, 0.5–1 mm high, glabrous, margin undulate. Pistil glabrous, 5–5.5 mm long; ovary cylindrical, 2–2.5 mm long; style 2.5–3 mm long, nearly as long as ovary; stigma 2, oblate. Capsule linear, glabrous, 2–2.5 cm long.

Additional specimens examined: — CHINA. Chongqing: Wuxi County, Lanying Grand Canyon, Yintiaoling National Nature Reserve , 31°26′19″N, 109°52′16″E, elev. ca. 1060 m, 16 June 2022, Feng Chen YTL22-731 (paratypes IBK00445396 !, CQNM0025461 !); Wuxi County , Hongqi, Yintiaoling National Nature Reserve , 31°31′18″N, 109°49′49″E, elev. ca. 1330 m, 7 April 2022, Chi Xiong XC 22-057 (paratype IBK00445398 !) .

Distribution and Ecology: —The new species is endemic to Wuxi County, northeast Chongqing Municipality, bordering Hubei and Shaanxi Province, China. It grows on shady damp moss-covered valley cliffs, at 1060–1670 m.

Phenology: —Flowering from May to June; fruiting from June to August.

Etymology: —The specific epithet ‘ wuxiensis ’ refers to the type locality where the new species was found, Wuxi County, Chongqing Municipality. The Chinese name is “Wū Xī Mǎ Líng Jù Tái (ĮḬḼḩssḕ)”.

Conservation assessment: —This new species is only found in the type locality and is presently known to occur in three populations with ca. 500 mature individuals. All known populations are located by the roadside, easily disturbed by human activities. Thus, following the IUCN Red List Categories and Criteria ( IUCN 2019), it is temporarily assessed as Vulnerable [VU D1 ].

Taxonomic affinities: — Oreocharis wuxiensis morphologically resembles O. giraldii in having leaf blade oblo ng-ovate, gray pubescent and rust-brown villous, margin coarsely dentate-serrate, corolla purplish-red, four fertile stamens, and two stigmas. It can be easily differentiated from O. giraldii by several characteristics, including the shape of the corolla tube and lobes, the absence of staminodes, the indumentum, length of pistil, and the size of the ovary and style. The detailed characteristics of the related species are provided in Table 1 .

Figures

FIGURE 1. Oreocharis wuxiensis sp. nov. A. Habitat; B. Plant with fruits; C. Inflorescence; D. Leaf blades; E. Flowers; F. Side view of a flower; G. Dorsal view of a flower; H. Ventral view of a flower; I. Opened corolla showing stamens; J. Pistil with disc and calyx lobes; K. Disc and ovary; L. Capsules. A, C–K were photographed by Chi Xiong, B, and D by Hou-Lin Zhou, and L by Feng Chen.

FIGURE 2. Morphological comparison of Oreocharis wuxiensis sp. nov. (1) and O. giraldii (2) A. Habit; B. Flowers; C. Side view of a flower; D. Dorsal view of a flower; E. Capsule; F. Opened corolla showing stamens; G. Pistil with disc and calyx lobes. A1 were photographed by Feng Chen, A2, and B2 by Yuan-Yuan Li, B1–G1, F2, G2 by Chi Xiong, and C2–E2 by Ren-Bin Zhu.