玉玄山茶 Camellia ngochuyeniae V. D. Luong & N. B. TrinhCamellia ngochuyeniae

Camellia ngochuyeniae V. D. Luong & N. B. Trinh in Dalat University Journal of Science Volume 16, Issue 2, 2026 64-75, DOI: http://doi.org/10.37569/DalatUniversity.16.2.1573(2026)

Type:—VIETNAM. Hoa Binh Province, Luong Son District, Cao DuongCommune, mixed wood-bamboo forest at an elevation of 270 m, December 2022, Nguyen Van Thanh, Do Cao Phong DL221209 (holotype DLU, isotype VAFS).

Description: Small-to-medium trees 3.0–7.5 m tall, twigs sparsely pubescent, purple. Mature leaves stalked, oblong-elliptic or elliptic, 10.0–21.0 cm long, 3.5–7.5 cm wide, thickly coriaceous; apices long-acuminate or caudate; bases obtuse to nearly round, margins serrate; upper sides dark green, shiny and glabrous; undersides paler green, glabrous; midribs protruding on the plural side; lateral veins sunken on upper sides, protruding on the undersides; secondary venation 10–12 pairs, pinnate; petioles falcate, slightly curved, 1.0–1.5 cm long, sparsely pubescent. Flowers axillary solitary or in groups of 2–4 on young shoots, nodding, 6.5–8 cm in diameter; pedicels 0.7–1.1 cm long, stout, thickened upwards, sparsely pubescent; bracteoles 4–5, suborbicular to orbicular, 2.5–4.5 mm long, 2.0–4.5 mm wide, outer surfaces densely velutinous, inner surfaces glabrous, ciliate, persistent. Sepals 5–7(–8), suborbicular or subglobose, 0.5–1.4 cm long, 0.7–1.5 cm wide, outer surfaces densely velutinous, inner surfaces glabrous, margins ciliate, persistent. Petals 12–15, subglobose to broadly obovate, pink with narrow white margins, 1.2–4.0 cm long, 2.5–3.3 cm wide, outer surfaces densely velutinous, inner surfaces glabrous, innermost petals united with outermost filaments 0.7–1.0 cm at the bases. Androecium numerous, arranged in 5–6 circles, filaments 2.0–2.5 cm long, light yellow, pubescent along two-thirds of their length, outer filaments united 1.0–1.5 cm at the bases; anthers light yellow, dorsifixed. Gynoecium superior, ovaries 4–5 locular, ovate, ribbed, 4.0–5.0 mm long, 4.0–5.5 mm wide, tomentose; styles 4–5, free to the base, 1.5–1.8 cm long, tomentose halfway from the bases. Capsules flattened globose, 2.1–2.7 cm high, 5.5–6.5 cm wide, furfuraceous, sparsely pubescent, dehiscing distally into 4–5 parts, pericarps 3.0–4.0 mm thick when dry. Seeds 1–3 per locule globose or semiglobose, 1.4–1.8 cm wide, reddish brown, villous.

Phenology: Camellia ngochuyeniae flowers from December to February (next year) and fruits from June to August.

Distribution, habitat, and conservation status: Camellia ngochuyeniae has been discovered at two locations in Luong Son and Kim Boi District of Hoa Binh Province. The area of occupancy is less than 10 km2, and the total population is fewer than 200 mature individuals. Therefore, it was assessed as Critically Endangered (CR B2ab (iii, v)) according to the IUCN categories and criteria (IUCN, 2025).

Etymology: The epithet honors the discoverer’s daughter, Mrs. Do Ngoc Huyen.

Vernacular name: Trà ngọc huyền.

Additional specimens examined:—VIETNAM. Hoa Binh Province, Kim Boi District, Hop Tien Commune, mixed wood-bamboo forest at an elevation of 400 m, December 2024, Luong Van Dung DL241219 (DLU).

VIET NAM:  Luong Son and Kim Boi District of Hoa Binh Province

玉玄山茶 Camellia ngochuyeniae V. D. Luong & N. B. Trinh. 该新种发表于《大叻大学科学杂志》第16卷第2期，2026年第64-75页，DOI: http://doi.org/10.37569/DalatUniversity.16.2.1573(2026).

模式标本：越南和平省良山縣高阳社，混合竹木林，海拔270米，2022年12月，Nguyen Van Thanh 与 Do Cao Phong 采集，标本号 DL221209（主模式存于大叻大学标本馆 DLU，等模式存于越南林业科学研究院标本馆 VAFS）。

形态描述： 小至中型乔木，高3.0–7.5米；小枝疏被短柔毛，紫色。成熟叶具柄，长椭圆形或椭圆形，长10.0–21.0厘米，宽3.5–7.5厘米，厚革质；先端长渐尖或尾状；基部钝至近圆形，边缘具锯齿；上面深绿色，有光泽，无毛；下面淡绿色，无毛；中脉在两面突起；侧脉在上面凹陷，在下面突起；二次脉10–12对，羽状；叶柄镰刀形，微弯曲，长1.0–1.5厘米，疏被短柔毛。花腋生，单生或2–4朵簇生于幼枝上，下垂，直径6.5–8厘米；花梗长0.7–1.1厘米，粗壮，向上增粗，疏被短柔毛；小苞片4–5枚，近圆形至圆形，长2.5–4.5毫米，宽2.0–4.5毫米，外面密被短绒毛，内面无毛，边缘具缘毛，宿存。萼片5–7（–8）枚，近圆形或近球形，长0.5–1.4厘米，宽0.7–1.5厘米，外面密被短绒毛，内面无毛，边缘具缘毛，宿存。花瓣12–15枚，近球形至宽倒卵形，粉红色，具狭窄白色边缘，长1.2–4.0厘米，宽2.5–3.3厘米，外面密被短绒毛，内面无毛，最内层花瓣与最外层花丝基部合生0.7–1.0厘米。雄蕊多数，排列成5–6轮，花丝长2.0–2.5厘米，淡黄色，沿长度三分之二被柔毛，外层花丝基部合生1.0–1.5厘米；花药淡黄色，背部着生。雌蕊上位，子房4–5室，卵形，具棱，长4.0–5.0毫米，宽4.0–5.5毫米，被绒毛；花柱4–5枚，自基部完全分离，长1.5–1.8厘米，从基部起一半长度被绒毛。蒴果扁球形，高2.1–2.7厘米，宽5.5–6.5厘米，被糠秕状鳞片，疏被短柔毛，从顶部向基部4–5瓣开裂，果皮干时厚3.0–4.0毫米。种子每室1–3粒，球形或半球形，宽1.4–1.8厘米，红褐色，被长柔毛。

物候期：玉玄山茶Camellia ngochuyeniae的花期12月至次年2月，果期6月至8月。

分布、生境与保护现状：玉玄山茶目前已知分布于和平省良山縣与金杯縣的两个地点。占有面积小于10平方公里，总种群成熟个体数少于200株。因此，根据IUCN（2025）的分类标准和准则，其保护等级被评估为极危（CR B2ab (iii, v)）。

词源： 种加词“ngochuyeniae”以纪念发现者的女儿杜玉玄（Do Ngoc Huyen）的名字命名。

越南语名：Trà ngọc huyền。

其他标本：越南和平省金杯縣合进社，混合竹木林，海拔400米，2024年12月，Luong Van Dung 采集，标本号 DL241219（存于大叻大学标本馆 DLU）。

越南和平省金杯縣合进社和良山縣高阳社