Oreocharis tsaii Y. H. Tan & J. W. Li, 2015

Tan, Yun-Hong, Li, Jian-Wu & Yin, Jian-Tao, 2015, Oreocharis tsaii, a new species of Gesneriaceae from southern Yunnan, China, Phytotaxa 195 (2), pp. 188-192 : 188-192

Oreocharis tsaii Y. H. Tan & J. W. Li , sp. nov. ( Figs. 1–2 ).

Diagnosis: Oreocharis tsaii is similar to O. hirsuta Barnett , differing from the later by its smaller cordate to ovate leaves; cymes with 1–5 flowers, corolla tube narrowing gradually from base to throat, constricted at the throat, corolla lobes mostly more than half as long as the tube; filaments sparsely glandular-pubescent and pilose, style sparsely glandular-pubescent.

Type:— CHINA. Yunnan: Menglian, Mengma, Lafu, growing on rocks or cliffs in valleys under evergreen broad-leaved forests, 1500 m, 31 Oct. 2010, Yun-Hong Tan 3308 (holotype HITBC!, isotype HITBC!).

Perennial, rosette herbs. Stemless. Leaves basal, spirally arranged, 5–20, petiolate; petioles terete, 0.5–5.0 cm long, 1.5–3 mm in diameter, densely reddish brown villous and glandular hairy, 2–4 mm long; leaf blades papery when dry, cordate to ovate, 1.3 × 1.2–5.5 × 4.0 cm, bases subcordate to cordate, slightly unequal, margins crenate, apices obtuse to acute, adaxially densely reddish brown villous hairy, abaxially densely villous along veins, hairs 4–5 mm long; midrib usually emerald when fresh, lateral veins 4–5 on each side of midrib, distinct, concave adaxially, prominent abaxially. Inflorescences cymes, axillary, 1–2-branched, 1–5-flowered; peduncles 3.0–11.0 cm long, ca. 1 mm in diameter, pilose and sparsely glandular hairy; bracts 2, 3.5 × 0.8–5.5 × 1.0 mm, lanceolate to linear-lanceolate, margins entire or 2–3- denticulate, pilose and sparsely glandular hairy outside, hairs 2–3 mm long; bracteoles similar but smaller, 2.5 × 0.5–3.0 × 0.7 mm; pedicels 0.6–2.1 cm long, 0.6–0.8 mm in diameter, with 2–2.5 mm long dense and glandular pubes. Calyx actinomorphic, 3.0 × 0.8–4.0 × 1.0 mm, (4–)5(–6)-parted to base, slightly unequal, lobes elliptic to linear-lanceolate, pilose and with glandular hairy outside and glabrous inside, margins entire or 1–3-denticulate. Corolla yellow 1.7–2.0 cm long, outside densely glandular-pubescent, inside glabrous; tube cylindrical, narrowing gradually from base to throat, constricted at the throat, 10–13 mm long, 4.5–5.0 mm in diameter at base and 2.0–3.0 mm in diameter at the throat; limb distinctly two-lipped, adaxial lip 2-lobed to base, lobes obovate to elliptic, 4.0 × 2.5–7.0 × 7.0 mm; abaxial lip (2–)3-lobed to base, lobes obovate to elliptic, 6.0 × 2.5–9.0 × 7.8 mm. Stamens (3–)4, adnate to corolla 4.0–5.0 mm above base, included; filaments 6.0–7.0 mm long, slender, sparsely glandular-pubescent and pilose, free; anthers oblong, 0.8 × 0.5–1.0 × 0.7 mm, 2-loculed, dehiscing longitudinally, connective glabrous; staminode 1, glabrous, 1.5–2.0 mm long, adnate to 5 mm above corolla tube base. Disc ring-like, 1.0– 1.5 mm high, glabrous, entire or subentire. Pistil 6.0–10.0 mm; ovary 4.0–8.0 mm long, ca. 1 mm in diameter, style 1.0–2.0 mm long, sparsely glandular-pubescent; stigma peltate, orbicular, 1.0– 1.5 mm in diameter. Capsules 4-angled or subterete, 1.5–2.1 cm long and ca. 2 mm in diameter, glabrous. Flowering from October to November and fruiting from November to December.

Distribution, habitat and ecology:— Oreocharis tsaii is only known from southern Yunnan and grows on rocks or cliffs in valleys, at an elevation of ca. 1400–1500 m. The main herbaceous companion species are: Begonia menglianensis Y. Y. Qian , Henckelia speciosa (Kurz) D.J.Middleton & Mich.Möller , Petrocosmea parryorum C. E.C.Fisch. , Asplenium normale Don , Cornopteris decurrenti-alata (Hook.) Nakai , Selaginella siamensis Hieron. , and Carex cruciata Wahlenb.

Relationships:— Oreocharis tsaii is morphologically most similar to O. aurea and O. hirsuta Barnett from Thailand ( Barnett 1961). After comparison with the specimens and literature of O. hirsuta and O. aurea , we found that O. tsaii can be clearly differentiated from both by several characters, as described in the diagnostics above and summarized in Table 1.

Proposed IUCN conservation assessment. —Endangered (EN B1ab(iii)). This species is only known from two nearby sites. The currently known Extent of Occurrence is less than 200 km 2 and the population size is less 1000 individuals. The known populations are all in disturbed and fragmented habitats.

Etymology:— The specific epithet commemorates the late Prof. Cai Xitao (Tsai Hse-Tao), who devoted all his life to the study of Chinese plants and Xishuangbanna Tropical Botanical Garden (XTBG).

Additional specimens examined (paratypes):— CHINA. Yunnan: Menglian County, Mengma, Lafu, 31 Oct. 2010, Jian-Wu Li cx00019 (HITBC). 20 Nov. 2013, Yun-Hong Tan 10059 (HITBC).

Figures

FIGURE 1. Oreocharis tsaii. A. Habit. B. Leaf. C–F. Corolla shapes. G–J. Opened corolla showing stamens and staminode. K–L. Calyx. M. Pistil. N. Capsule. Photographed by Yun-Hong Tan.

FIGURE 2. Oreocharis tsaii. A. Habit. B. Leaf (abaxial). C. Flower, lateral view. D–F. Corolla shapes. G–I. Opened corolla showing stamens and staminode. J–M. Calyx.N. Stamen.O–P. Pistil. Q. Capsule. Illustration by Bi-Dan Lai based on the holotype Yun-Hong Tan 3308.