德保金花茶 Camellia debaoensis R.C.Hu & Y.Q.LiufuCamellia debaoensis

Camellia debaoensis R.C.Hu & Y.Q.Liufu. First published in PhytoKeys 135: 50 (2019).  Description. Shrubs, 1–3 m tall. Young branches cylindrical, thick, glabrous, yellowish brown or grayish brown, and current year branchlets purplish red. Leaf blade leathery, ovate to long ovate, 6–13 × 3–5 cm, adaxial surface dark green and glabrous, abaxial surface pale green, brown glandular punctuate and veins sparsely spreading villous, veins abaxially elevated and adaxially impressed, secondary veins 5–6 on each side of midvein and connected at the proximal edge, base cuneate to broadly cuneate, apex caudate tip, margin serrulate; petiole 5–12 mm long, glabrous. Flowers subterminal axillary, solitary, 3–4.5 cm diam. Pedicel ca. 4(–6) mm long, thick; bracteoles 4 (or 5), unequal, 1–3 × 2–4 mm, appressed and covering pedicel, oval-triangle, leathery, green and glabrous, margin ciliolate. Sepals 5 (–6), semiorbicular to broadly ovate, 3–5 × 5–8 mm, leathery, glabrous, lightly yellow and occasionally with pink patches, fruiting stage green, margin ciliolate. Petals 10, in three whorls of 3–4 petals, golden yellow, glabrous; outer 3 or 4 petals suborbicular, occasionally with pink patches, 0.7–1.1 × 1 cm; inner orbicular-ovate or oval, 1.2–1.8 × 1.2–2.6 cm, basally connate for 1–3 mm. Stamens numerous, glabrous, ca. 2 cm long; anthers ca. 3 × 1mm; outer filaments connate ca. basal 1/4, ca. 1.6 cm, inner filaments nearly distinct, ca. 1.7 cm. Ovary cylindrical, ca. 2 mm in diam., glabrous, 3-loculed; style 2 cm long, glabrous, base connate, apex 3-lobed to 1/6 style length. Capsule triangle oblate, glabrous, 1.4–1.6 × 1.6–2.8 cm; Seeds brown, hemispherical, pubescent. Phenology. Flowering from December to February of the next year; fruiting from July to August. Distribution and habitat. Camellia debaoensis grows at the entrance of one of the limestone caves in the karst region of Debao County (Fig. 3), Guangxi, China, accompanied by Ageratina adenophora  (Sprengel) R. M. King & H. Robinson (Compositae), Boehmeria penduliflora Wedd. ex Long (Urticaceae), Fallopia multiflora (Thunb.) Harald (Polygonaceae), Flueggea virosa (Roxb. ex Willd.) Voigt (Euphorbiaceae), Pteris vittata L. (Pteridaceae), Ficus tikoua Bur (Moraceae), and Pueraria montana (Lour.) Merr. var. lobata (Willd.) Maesen et S. M. Almeida ex Sanjappa et Predeep (Fabaceae). Conservation status. According to currently available data, Camellia debaoensis is only found in its type locality and there are only nine adult trees and four saplings, with the distribution restricted to a very limited region (less than 200 m2). Considering this situation, we consider Camellia debaoensis as ‘Critically Endangered’ (CR) based on the IUCN categories and criteria (IUCN 2017).

Camellia debaoensis resembles many other yellow-flowering camellia species with connate style, such as Camellia pubipetala Y. Wan & S.Z. Huang, C. mingii S.X. Yang, C. tuyenquangensis D.V. Luong, N.N.H. Le & N. Tran, C. oconariana Orel, Curry & Luu, C. thuongiana Luong, Anna Le & Lau, C. luteocerata Orel, C. luteopallida Luong, T.Q.T. Nguyen & Luu, C. bugiamapensis Orel, Curry, Luu & Q.D. Nguyen and C. capitata Orel, Curry & Luu. These species are placed in various sections within the genus including sections Stereocarpus Chang, Chrysantha Chang, Dalatia Orel and Capitatae Orel (Table 1). A key to identifying species of yellow camellia with connate style is provided below. Of these species, the new species is more similar to C. pubipetala, C. mingii, C. tuyenquangensis than to other species by sharing small leaflets, subterminal axillary flowers, 9–13 petals, differentiated bracts, outer filament whorl basally connate, 3-locular ovary, connate style. However, it is well distinguished from these species in having glabrous young branches, glabrous petiole, glabrous sepals, glabrous petals, glabrous stamens and a glabrous ovary (vs. villous in C. pubipetala and C. mingii), 10 petals (vs. 9–13 in C. pubipetala, 12–13 in C. mingii and 12 in C. tuyenquangensis), cylindrical ovary (vs. ovoid in C. mingii and C. tuyenquangensis, spherical in C. pubipetal) and style 3-lobed to 1/6 style length (vs. 3 (or 4)-cleft to 1/3 style length in C. pubipetala, 3-cleft to 1/10 style length in C. mingii, 3-cleft to 1/2 style length in C. tuyenquangensis). The comparisons between C. debaoensis and these species are provided in Table 2. Based on hairs, lamina length, flower size, number of carpels and other characteristics, the new species is also a taxonomic entity distinct from C. oconariana, C. thuongiana, C. luteocerata, C. luteopallida, C. bugiamapensis and C. capitata

德保金花茶Camellia debaoensis R. C. Hu et Y. Q. Liufu南宁市金花茶公园，2021.《国内外金花茶物种图鉴》，广西科学技术出版社，第50-51页。【形态特征】常绿灌木，高1.0-3.0m。树皮灰白色。嫩枝圆柱形，紫棕色，无毛；老枝黄棕色或浅灰棕色。叶芽锥形，绿色。老叶革质，卵形或长卵形，长5.8-12.9cm，宽3.2-5.4cm，叶缘有不明显小锯齿并呈轻微波浪形，先端尾状渐尖，基部楔形至宽楔形，正面深绿色，背面浅绿色有黑色腺点；侧脉5-6对；主脉和侧脉在叶面凹陷，在叶背凸起；网脉在叶两面均明显可见；叶肉在叶面稍微隆起；叶柄长0.5-1.1cm，无毛。花蕾近球形。花黄色，单生或2-3朵簇生，顶生或腋生，直径3.4-4.8cm；花梗长0.5-0.7cm；苞片4-5枚，椭圆形；萼片5-6枚，浅橄榄绿色，偶有粉红色，半圆形，边缘有短茸毛，宿存；花瓣8-11枚，卵形、长卵形或近圆形，最外轮花瓣基部有少量浅红色斑块，瓣面脉纹不明显；花丝长1.6-2.2cm，4-5轮筒状排列，外轮基部与花瓣合生，内轮离生，无毛；花药黄色，椭圆形；花柱3条，长1.5-1.8cm，先端约1/5开裂，下部合生，无毛；子房扁球形，光滑无毛，3室。蒴果三角状扁球形，绿色带橄榄棕色，光滑，直径1.8-4.8cm，高1.5-3.1cm，重12.5-33.2g，果皮厚1.6-2.8mm。种子每室2-3粒，半球形或三角状球形，深棕色，被棕色短茸毛。花期12月至翌年2月，果熟期7-8月。【原产地】该种是中国的一个特有种，分布于广西德保、靖西，生长在海拔760-800m的石灰岩常绿阔叶林中。【识别要点】该种叶片卵形或长卵形，叶缘呈轻微波浪形；最外轮花瓣基部有少量浅红色斑块，花柱先端约1/5开裂，下部合生。