Oreocharis aimodisca Lei Cai, Z.L.Dao & F.Wen, 2020

Cai, Lei, Huang, Zhang-Jie, Wen, Fang & Dao, Zhi-Ling, 2020, Two new species of Oreocharis (Gesneriaceae) from karst regions in Yunnan and notes on O. tetraptera and O. brachypoda from China, PhytoKeys 162, pp. 1-12 : 1

Oreocharis aimodisca Lei Cai, Z.L.Dao & F.Wen sp. nov. Figures 1 , 2 , 3

Diagnosis.

Oreocharis aimodisca is morphologically similar to O. longifolia (Craib) Mich. Möller & A.Weber and O. muscicola (Diels) Mich. Möller & A.Weber in the appearance and colour of its flowers, but differs from the latter two species in its leaf blade oval to ovate, base cordate or auriculate, margin crenate, peduncle densely brown villous and pubescent, corolla outside densely pubescent and four separated fertile stamens, pistil densely pubescent and disc blood red.

Type.

China. Yunnan: Shizong County, Wulong Town, Dachang Village, Xiaofakuai, 24°39'N, 104°10'E, elev. ca. 2122 m, on the surface of wet rocks, in flower, 10 September 2019, Lei Cai & Pin Zhang CL275 (holotype: KUN!, isotypes: KUN!, IBK!).

Description.

Perennial herb, rhizome 5-18 mm long, 3-5 mm in diameter. Leaves 6-18, basal, petiole 2.5-10.5 cm long, brown villous and pubescent, leaf blade oval to ovate, 2.5-7.0 × 1.8-5.5 cm, adaxially densely appressed pubescent, abaxially puberulent, densely brown pubescent along veins, lateral veins 3-6 on each side of midrib, adaxially inconspicuous, abaxially conspicuous, apex acute, base cordate or auriculate, slightly oblique sometimes, margin crenate. Cymes axillary 2-5, inflorescence 1-5-flowered; peduncle 5.5-16 cm long, brown villous and pubescent; bracts 2, lanceolate to narrowly triangle, 5-8 × 1.5-2.8 mm, outside brown pubescent, inside glabrous, margin nearly entire to denticulate; pedicel 1.2-3.5 cm long, densely pubescent. Calyx 8-12 mm long, 5-lobed to the base, lobes unequal, linear-lanceolate or narrowly triangular, 8-12 × 1.5-2.2 mm, both sides densely pubescent, margin denticulate. Corolla yellow, 2.8-3.6 cm long, outside densely pubescent, inside puberulent in the throat and on adaxial lobes, the lower part forms red stripes on the throat and lobes, tube coarsely tubular, gradually expanded from base to the throat, 2.0-2.6 cm long, 6-10 mm in diameter; limb 2-lipped; adaxial lip 2-lobed to middle, semicircular, lobes 4-5 × 4-5 mm, abaxial lip 3-lobed to middle, semicircular, 5-6 × 5-7 mm. Stamens 4, 1.5-1.8 cm long, adnate to corolla 4-7 mm from the base; filaments linear, sparsely pubescent; anthers oblong, 2-loculed, dehiscing longitudinally, connective glabrous; staminode 1, 0.6-0.8 mm long, inserted ca. 3 mm from the base. Disc ca. 1.2 mm high, blood red, margin undulate. Pistil 1.6-2.4 cm long; ovary long cylindrical, densely pubescent, 1.0-1.4 cm long; style 6-10 mm long, densely pubescent; stigma bilobed, flabellate. Capsule linear, 3.5-4.8 cm long.

Phenology.

Flowering from August to September; fruiting from September to December.

Distribution and habitat.

Oreocharis aimodisca is currently known from two adjacent populations at the type locality, Shizong County, East Yunnan, China. The new species commonly growing with other plants in shady and wet places on the middle part of mountain slopes under primary evergreen broad-leaf forest and shrubbery on karstic limestone at an elevation of over 2000 m.

Etymology.

The original specific epithet ' aimodisca ' derives from the Greek ‘αίμα’ meaning blood red and ‘δίσκος’ meaning discus.

Vernacular name.

The Chinese name of the new species is “Diān Dōng Mǎ Líng Jù Tái” (滇东马铃苣苔). The first two words, “Diān Dōng,” mean east of Yunnan, the next four words, "Mǎ Líng Jù Tái,” mean Oreocharis in Mandarin.

Conservation status.

Based on our field investigations, the new species is currently only known from the type locality with two contiguous subpopulations, in total ca. one thousand mature individuals were present within 5000 m2 (AOO). Since no special surveys were carried out for delimiting its distribution and information about threats is not very clear, this species was provisionally considered to be Critically Endangered [CR B2(a)] in terms of the IUCN Red List Categories and Criteria ( IUCN 2019).

Taxonomic affinities.

Oreocharis aimodisca is morphologically similar to O. longifolia and O. muscicola in the corolla yellow and coarsely tubular; however, it is different from the latter two species by the shape of the leaf blade, indumentum characters of the peduncle, pedicel, calyx, corolla and pistil and separated stamens. The comparison of morphological characters on related species is provided in Table 1 .

Figures

Figure 1. Oreocharis aimodisca Lei Cai, Z. L. Dao & F. Wen, sp. nov. A habit B pistil with disc and calyx C old capsule D front view of flower E opened corolla showing stamens and staminode F side view of a flower G adaxial view of the anther. Drawn by Xuan-Lin Zhu.

Figure 2. Oreocharis aimodisca Lei Cai, Z. L. Dao & F. Wen, sp. nov. in natural habitat A, B plants with flowers in the wild C habitat. Photographed by Lei Cai.

Figure 3. Oreocharis aimodisca Lei Cai, Z. L. Dao & F. Wen, sp. nov. A habit B adaxial (lower half) and abaxial leaf surface (upper half) C side view of a flower D front view of flowers E pistil with disc and calyx F opened corolla showing stamens and staminode G opened corolla with pistil and calyx H fresh fruits I old capsules. Photographed by Lei Cai.