Oreocharis corallodiscoides Huan C. Wang & Xi Li, 2025

Li, Xi, Wang, Qiu-Ping, Yang, Feng, Ye, Jing-Yi & Wang, Huan-Chong, 2025, Oreocharis corallodiscoides (Gesneriaceae, Trichosporeae, Didymocarpinae), a new species from Yunnan, southwest China, PhytoKeys 256, pp. 73-81 : 73-81

Oreocharis corallodiscoides Huan C. Wang & Xi Li sp. nov.

Figs 1 , 2 , 3

Diagnosis.

Oreocharis corallodiscoides is similar to O. agnesiae (Forrest ex W. W. Sm.) Mich. Möller et W. H. Chen in texture and indumentum of the leaves, as well as in flower morphology and size, but can be clearly distinguished from the latter by its leaves ovate, rounded or sometimes rhombic (vs. ovate to oblong), with a length-to-width ratio of 1–1.5 (vs. 2.2–2.7), corollas yellow (vs. purple-red), and the presence (vs. absence) of two purple and triangular appendages inside the base of the corolla tube. Additionally, while O. corallodiscoides shares the inflated yellow corolla tube with O. longifolia , it differs by its ovate-rotund leaves (vs. lanceolate-oblong), shorter petioles (0.5–2 cm vs. 3.5–5 cm), crenate leaf margins (vs. serrate), glandular pistils (vs. glabrous), and the presence of appendages with thickened filaments.

Type.

China • Yunnan province, Yimen county, Luzhi town, near Xiaoluzhi village , 24°40'N, 101°57'E, 1300–1400 m a. s. l., 25 th Sept. 2015, H. C. Wang et al. YM 239 (Holotype: YUKU [2074890]!; isotypes: KUN, YUKU) .

Description.

Herbs perennial. Rhizome inconspicuous, with numerous fibrous roots. Leaves 9–18 in basal rosette, petiolate; petiole complanate, 0.5–2 cm long, both surfaces with densely appressed multicellular hairs; leaf blade ovate, rotund, or sometimes rhombic, 2.2–3.5 × 1.1–2.2 cm, coriaceous when dried; apex rounded, base broadly cuneate to rounded, margins crenate, adaxial surfaces densely white to gray strigose, abaxial with densely appressed multicellular hairs; lateral veins 4 or 5 on each side of midrib, adaxially inconspicuous, abaxially conspicuous. Cymes 1–2 (– 4), scapiform, 1 - flowered; peduncles 4–7 cm long, with dense glandular hairs; bracts 2, inserted above middle of cymes, elliptic to lanceolate, 2.0–4.0 × ca. 1.0 mm, with entire margins, outside with glandular hair, inside nearly glabrous; pedicels 2–3 cm long, with dense glandular hairs. Calyx 5 - parted to near base, narrowly triangular, apex acute, margin entire, outside with glandular hair, inside nearly glabrous, sepals unequal, 4–6 mm long. Corolla yellow, not spotted or striped, 2.0– 3.5 cm long, ca. 1–1.2 cm wide at mouth, outside covered with glandular hairs, glabrous inside; tube 1.5–2.5 cm long, inflated, infundibuliform and slightly curved downwards, two triangular purple appendages attached to base of tube, ca. 3 mm long, 2 mm wide at the base, apex acute; limb 5–6 - lobed, distinctly 2 - lipped, adaxial lip 4–6 mm long, unlobed, apex with 3 teeth, abaxial lip 7–8 mm long, 3 - lobed, lobes wide triangular, 3–4 mm wide, apex acuminate; disk ring-like, ca. 1 mm in height; fertile stamens 4, adnate to corolla base, coherent in pairs, included, filaments ca. 2 cm in length; staminode 1, ca. 1 cm in length, with glandular hairs, degenerate anthers reniform. Pistil with glandular hairs, 2–2.5 cm long, ovary long cylindrical, light yellow, 1 - loculed, style 1–2 mm long, stigma bilobed. Capsule oblanceolate-oblong, 4–6 cm long, commonly one side of the capsule dehiscing first.

Phenology.

Oreocharis corallodiscoides was observed flowering from August to September, and fruiting in October.

Etymology.

The specific epithet corallodiscoides is derived from the generic name Corallodiscus Batalin (Gesneriaceae) by adding the suffix “ - oides ”, reflecting the leaf morphological similarity of this new species to some members of the genus Corallodiscus, such as C. lanuginosus (Wall. ex A. DC.) B. L. Burtt; particularly, its sometimes rhombic leaves are rare in the genus Oreocharis.

Vernacular name.

Shan hu ye fo du ju tai (珊瑚叶佛肚苣苔) (Chinese).

Distribution and ecology.

Oreocharis corallodiscoides is known only from Xiaoluzhi village in the Luzhijiang valley, Yimen county, Yunnan province, southwest China. Its habitat is characterized by seasonally hot and arid conditions, occurring on dry slopes within the valley (Fig. 3 ). The species is typically found in limestone grasslands at elevations ranging from 1,300 to 1,400 meters, where water availability is limited. Additionally, Oreocharis corallodiscoides often grows together with Corallodiscus lanuginosus (Wall. ex A. DC.) B. L. Burtt , and interestingly, these two species of different genera have very similar leaf shapes and indumentum (Fig. 3 B ).

Conservation status.

Oreocharis corallodiscoides is a rare species with a restricted geographical range and a small population size. It is currently known only from the upstream region of the Luzhijiang river in Yimen county, an area that lies outside any officially protected zone. Based on the IUCN Red List Categories and Criteria (Version 16) (IUCN, 2024), the species meets Criterion D (very small or restricted population), with total mature individuals fewer than 250 mature individuals. Thus, this newly described species is preliminarily assessed as Endangered (EN).

Figures

Figure 1. Oreocharis corallodiscoides sp. nov. A habit B adaxial surface of leaf C abaxial surface of leaf D flower (side view) E style, stamens and two triangular purple appendages F immaturate capsule.

Figure 2. Oreocharis corallodiscoides sp. nov. A, B habit C flower in front view D flower in side view, pedicel E adaxial surface of leaf F abaxial surface of leaf G pistil and stamens H pistil, stamens and two triangular purple glandular appendages (at the arrow) I immaturate capsule J mature capsule.

Figure 3. Habitat of Oreocharis corallodiscoides sp. nov. A overview of the Luzhijiang valley showing the type locality (indicated by red arrow) B close-up of the fruiting habitat (Oreocharis corallodiscoides and Corallodiscus lanuginosus are indicated by red and blue arrows respectively C close-up of the xeric habitat during the dry season.