Oreocharis yangjifengensis F.Wen & B.Chen, 2023

Li, Rui-Feng, Le, Xin-Gui, Xu, Lin, Maciejewski, Stephen, Chen, Bin & Wen, Fang, 2023, Oreocharis yangjifengensis (Gesneriaceae), a new species from Yangjifeng National Nature Reserve of Yingtan City, Jiangxi Province, China, Phytotaxa 583 (2), pp. 213-218 : 214-216

Oreocharis yangjifengensis F.Wen & B.Chen , sp. nov. ( Figs. 1 & 2 , Table 1 )

Diagnosis:— Oreocharis yangjifengensis ( Fig.2 A–C ) can be easily distinguished from all other Oreocharis species by having zygomorphic and urceolate corolla with mauve color. It is the most similar to O. maximowiczii ( Fig.2 D–F ) in the leaf characteristics, but can be distinguished from the latter by its leaf blade abaxially densely pubescent to villous (vs. abaxially densely brown silky to woolly), peduncle and pedicel densely erect pale brown pubescent (vs. sparsely pubescent or brown woolly and glandular-pubescent), corolla 0.8–1.0 cm long, urceolate, outside densely pubescent (vs. 2.0– 2.5 cm long, narrowly campanulate to broadly tubular, outside nearly glabrous), pistil 1.2–1.4 mm long, pistil exsert corolla ca. 5 mm (vs. 1.6–2.5 mm long, pistil usually included, occasionally slightly exserted or not exserted).

Type:— CHINA, Jiangxi: Yingtan City, Guixi County, Yangjifeng National Nature Reserve , 27°96′N, 117°28′E, elev. ca. 603 m, 30 April 2021, Chen Bin, CSH42565 (Holotype IBK!; Isotype CSH!) .

Description:— Perennial herb. Leaves (7–) 9–13 or more, all basal; petioles 0.7–3.5 cm long, ca. 3.0 mm in diam., covered with short glandular hairs and densely brown woolly hairs; leaf blade coriaceous or stiffly chartaceous, ovate to ovate-orbicular, occasionally narrowly elliptic, apex rounded to acute, base cuneate to rounded, 4.0–9.0 × 2.5–4.5 cm, left-right asymmetric, occasionally symmetric, margin conspicuously irregular serrate, adaxially conspicuously bullate, dark green, densely pubescent, abaxially pale green, densely brownish pubescent to villous, especially along veins; lateral veins 7–9 on each side of the midrib, impressed adaxially and prominent abaxially. Cymes (2–)4–6 or more, axillary, 1–2-branched, 8–10 or more flowers per cyme; peduncle 6.0– 10 cm long, ca. 3.0 mm in diam., densely pale brown pubescent; bracts 2, opposite, lanceolate to subulate, 3–4 × 1–2 mm, entire, both sides densely pale brown woolly to pubescent; pedicel 0.5–2.0 cm long, ca. 2.0 mm in diam., densely pale brown woolly to pubescent; calyx 5- parted to the base, actinomorphic, sepals lanceolate-linear, 3.0–5.0 × 1.0– 1.5 mm, both sides densely brown pubescent. Corolla with mauve color at the apex and pale purple to white at the base; outside densely puberulent; zygomorphic, urceolate, swollen, ca. 8.0 mm in diam. at middle; orifice constricted, ca. 6.0 mm in diam.; limb 5-lobed, upper lip 2-lobed, lower lip 3-lobed, all lobes deltoid, 3.0–4.0 mm long, 2.0– 2.5 mm wide at the base, apex acute. Stamens 4, adnate the corolla base; filaments glabrous, 4.0–5.0 mm long, ca. 0.5 mm in diam.; staminode 1, ca. 1.5 mm long, adnate to the base of corolla tube; anthers pale brown, oblong, 2-locular, dehiscing longitudinally, 1.0–1.5 × 1.2–2.0 mm, glabrous. Disk annular, ca. 1.0 mm high, entire. Pistil 1.4–1.6 cm long, ca. 1.2 mm in diam., glabrous; ovary linear-oblong, 1–1.2 cm long, ca. 1.0 mm in diam.; style glabrous, ca. 4.0 mm long and 0.8 mm in diam.; stigma green, punctate, ca. 0.6 mm in diam. Capsule cylindrical, loculicidally dehisced to base, bivalved, ca. 2.2 cm long, glabrous.

Phenology:— Flowering from April to May; fruiting from July to August.

Distribution and habitat:— Oreocharis yangjifengensis is hitherto only known at elevation ca. 600 m in Yangjifeng National Nature Reserve, Guixi County, Yingtan City, Jiangxi Province, China, growing on moist and shaded rock surfaces.

Etymology:— The specific epithet ‘ yangjifengensis ’ is derived from its type locality, Yangjifeng National Nature Reserve.

Vernacular name:— Yáng Jì Fēng Mǎ Líng Jù Tái (OiỮWḼẅffṏ).

Provisional conservation status:— Since the small population of this fascinating species was found in Yangjifeng National Nature Reserve in 2021, we tried to search for additional populations in a five-kilometers radius around the type location five times. Unfortunately, no other population was found. The population consists of approximately 30 mature individuals and some young seedlings, all growing on the moist and shaded rock surface of a cliff in this Reserve. Even though the population is strictly protected in the Reserve, it still faces serious threats because of its small population size. The Area of Occupancy (AOO) is estimated at 200 m 2 (0.0002 km 2), and the Extent of Occurrence (EOO) is 109.46 km 2 (equal to approximately 10946 hectares, which is the area of the reserve) after five field surveys. Through multiple surveys, we believe that one of the main threats to the survival of this new species comes from the prolonged droughts caused by global warming, which might cause some plants to die. Based on its population status in the wild and following the IUCN Red List categories and criteria ( IUCN 2022), the new species is provisionally assessed as Critically Endangered [CR B2ab(iii)+C2a(ii)].

Notes:— Before this new species was discovered, there were a total of 12 species and 2 varieties of Oreocharis from East China (including Jiangxi, Jiangsu, Zhejiang, Shandong, Anhui, Fujian, Shanghai, and Taiwan), including O. auricula (S. Moore 1875: 229) C.B. Clarke (1883: 64) , O. auricula var. denticulata K.Y. Pan (1987: 276) , O. baolianis , O. benthamii C.B. Clarke (1883: 63) , O. burttii (W.T.Wang in Weitzman et al. 1997: 430) Mich.Möller & A.Weber in Möller et al. (2011: 18), O. chienii ( Chun 1946: 300) Mich.Möller & A.Weber in Möller et al. (2011: 18), O. curvituba J.J.Wei & W.B.Xu in Wei et al. (2016: 190) ( Feng et al. 2018), O. dalzielii (W.W.Sm. 1918: 171) Mich.Möller & A.Weber in Möller et al. (2011: 20), O. jiangxiensis (W.T. Wang 1986: 4) Mich.Möller & A.Weber in Möller et al. (2011: 22), O. maximowiczii C.B. Clarke(1883: 63) , O. maximowiczii C.B.Clarke var. mollis J.M.Li & R.Yi in Yi et al. (2019: 67), O. magnidens Chun ex K.Y. Pan (1987: 276) ( Feng et al. 2018), O. striata F.Wen & C.Z.Yang in Yang et al. (2015: 369) and O. tubiflora K.Y. Pan (1987: 287) . Significantly, the genus, Bournea Oliv. in Hooker (1893: tab. 2254), was correctly merged into Orocharis . One of the species in this genus, Bournea leiophylla (W.T. Wang 1975: 99) W.T.Wang & K.Y.Pan ex W.T.Wang in Wang et al. (1990: 135), which is distributed in East China, was restored as Oreocharis leiophylla W.T.Wang ( Möller et al. 2011) . Further, Bournea was revived by Chen et al. (2020) because it is well-known that two species of Bournea have a look-alike actinomorphic corolla, so their flowers are mistakenly thought to be dialypetalous. Considering the limitations of Chen et al.’s study in 2020 and the more detailed study by Lv et al. (2022) of Oreocharis xieyongii T.Deng, D.G.Zhang & H.Sun in Lv et al. (2022: 229), Bournea should still be regarded as one of the synonyms of Oreocharis . After carefully checking specimens of those taxa stored in herbaria and comparing their descriptions from FOC and the original documents ( Wang et al. 1998, Lin, 2016, Yang et al. 2015, 2020, Yi et al. 2019), O. yangjifengensis has a unique, zygomorphic urceolate corolla, while the rest have campaniform or tubular corolla.

On characteristics of vegetative organs, O. yangjifengensis is most similar to O. maximowiczii in having approximatively elliptical to ovate leaf blades and densely pubescent hairs on the adaxial leaf blade surfaces. Some living plants of both species are being cultivated in the nursery of Gesneriad Conservation Center of China and National Gesneriaceae Germplasm Resources Bank for observation. Apart from the above diagnosis, the detailed morphological comparisons of O. yangjifengensis and O. maximowiczii are provided in Table 1 and Fig. 2 , more photos of the new species are deposited in Chinese Field Herbarium website (https://www.cfh.ac.cn/spdb/TaxonNodeTree. aspx?spid=94840).

Figures

FIGURE 1. Oreocharis yangjifengensis F.Wen & B.Chen A. Habit; B. Habit with flowers; C1 & C2. Both side surfaces of leaf blades; D. Cyme and flowers; E. Lateral view of corolla; F. Stamens; G. Pistil; H. Opened corolla showing stamens and staminode; I. Capsule.

FIGURE 2. Comparison between Oreocharis yangjifengensis F.Wen & B.Chen (A–C) and O. maximowiczii C.B.Clarke (D–F). (A, D) The habit of flowering plants; (B, E) Flowering cymes; (C, F) Open flowers.