桂西短蕊茶 Camellia hainingii S.X.Yang et Y.S. HuangCamellia hainingii

Camellia hainingii S.X.Yang et Y.S. Huang, sp. nov., (Figs. 1 & 2). Type:—CHINA. Guangxi: Daxin County, Encheng National Nature Reserve, on limestone in the evergreen broad-leaved forest, elev. 180 m, 15 September 2020, S. X. Yang, P.M. Ye and F.Y. Wu 6389 (holotype KUN barcode 1541643; isotypes KUN, PE, IBK, IBSC, K).

Arbor, 5–12m tall; young branches reddish brown, glabrous; terminal buds glabrous or subglabrous. Leaves thinly leathery, oblong or narrow elliptic, 7.5–11.0 (–13.0) × 2.5–3.5 (–4.5) cm, apex acuminate to caudate with a tip ca. 1.0 cm long, base cuneate, margin sharply serration, adaxial surface dark green, shining and glabrous, abaxial surface yellow-green, glabrous, scattered dark brown cork-warts (sensu Sealy 1958), lateral veins 7–10 pairs, midvein, lateral veins and reticulate veins sunken adaxially and protruding abaxially, semitransparent; petiole 7–10 mm long, glabrous. Flowers axillary, solitary, subsessile, white or yellowish-white, 2.0–2.5 (–3.0) cm in diam; bracteoles and sepals 9–11, ovate, broad ovate to suborbicular, increasing in size upwards, 1.5–4.0 × 2.0–5.0 mm, abaxially green, glabrous, adaxially densely yellowish-white pubescent, margin narrow scarious and ciliate. Petals 6–8 in 2–3 whorls, outermost 2–3 sepaloid, the rests petaline, glabrous on both sides, suborbicular to elliptic, 6.0–13.0 × 6.0 mm, slightly connate at the base. Stamens numerous (80–110), 8.0–10.0 mm long, glabrous; outer filaments basally connate ca. 1/2–3/5 into a tube and adnate to the corolla for ca. 1.5 mm, inner filaments distinct, slender. Pistil ca. 4.0 mm long; ovary subglobose, 3-loculed, glabrous; style 3, free, very short, 1.5–2.0 mm long, glabrous. Capsule subglobose, grayish brown, ca. 2.0 cm in diam; pericarp <1.0 mm thick when dry, furfuraceous, splitting into 3 valves. Seeds 1 per locule, globose, ca. 1.0–1.5 cm in diam, dark brown, smooth. Fl. Sep.–Nov., fr. Jul.

Distribution, habitat, and conservation status Only one population of Camellia hainingii has been found in its type locality with a distribution of about 2 km2 and less than 100 individuals, at elevation of ca. 180 m in the evergreen broad-leaved forests in limestone area. Therefore, this species is accessed to be Critically Endangered (CR, B2a, b(v)) according to the IUCN Standards and Petitions Committee (2022) . Further field investigation is needed to confirm this assessment.

Etymology: The specific epithet is named after Dr. Hai-Ning Qin, a taxonomist special for Lardizabalaceae and wild plant conservation at Institute of Botany, Chinese Academy of Sciences. 

Vernacular name: 桂西短蕊茶  in Chinese.

Additional specimens examined (paratypes):—CHINA. Guangxi. Daxin County, Encheng National Nature Reserve, on limestone in the evergreen broad-leaved forest, elev. 180m,, 12 November 2018, S.X. Yang 5825 (KUN); same locality, 3 December 2019, S.X. Yang & F.Y. Wu 6311 (KUN); same locality, 15 September 2020, S. X. Yang, P.M. Ye and F.Y. Wu 6390, 6391, 6392, 6393 (KUN); same locality, 30 July 2021, S. X. Yang & E.D. Liu 6716 (KUN); Nanning, Nanning Golden Camellia Garden, cultivated, 22 September 2021, S.Y. Yang & P.M. Ye 6775 (KUN).

CHINA. Guangxi. Daxin County, Encheng National Nature Reserve

 桂西短蕊茶 Camellia hainingii S.X.Yang et Y.S. Huang。产广西大新县。

乔木，5-12米高；幼枝红棕色，无毛；顶芽无毛或近无毛。叶薄革质，长圆形或狭椭圆形， 7.5-11.0 (-13.0) x 2.5-3.5 (-4.5) 厘米，先端渐尖到尾状，顶端长约 1. 0厘米长，基部楔形，边缘有锐锯齿，正面深绿色，发亮无毛，背面黄绿色，无毛，散布暗褐色木栓疣（sensu Sealy 1958），侧脉7-10对，中脉、侧脉和网脉正面凹陷，背面突出，半透明；叶柄长7-10毫米，无毛。花腋生，单生，近无柄，白色或黄白色，直径2.0-2.5（-3.0）厘米；小苞片和萼片9-11，卵形，宽卵形到近圆形，向上增大， 1.5-4.0 x 2.0-5.0 毫米，背面绿色，无毛，正面密被黄白色短柔毛，边缘狭窄干膜质，具缘毛。花瓣6-8，2-3轮，最外层2-3萼片状，其余瓣状，两面无毛，近圆形到椭圆形， 6.0-13.0 x 6.0 毫米，基部稍合生。雄蕊多数（80-110），长 8.0-10.0 毫米，无毛；外花丝基部合生，长约 1/2-3/5，成筒状，花柱长约 3.5 毫米。外花丝基部合生，长约 1.5 毫米，内花丝长约 1.5 毫米。1.5毫米，内花丝离生，纤细。雌蕊长约4.0毫米；子房近球形，3室，无毛；花柱3，离生，极短，长1.5-2.0毫米，无毛。蒴果近球形，灰褐色，直径约 2.0 厘米；果皮干燥时厚<1.0 毫米，软鳞片状，裂成 3 裂爿。种子每室1粒，球状，直径约1.0-1.5厘米，暗褐色，平滑。花期9-11月，果期10-11月。花期9-11月，果期7-9月。花期9-11月，果期7月。

在其模式产地仅发现一个桂西短蕊茶的种群，分布面积约 2 平方公里，个体少于 100 个，位于海拔约 180 米的石灰岩地区的常绿阔叶林中。因此，根据IUCN（2022 ）标准，该物种被定为极危物种（CR, B2a, b(v)）。

广西大新县