平元山茶 Camellia nguyenii V. D. Luong & N. D. DoCamellia nguyenii

Camellia nguyenii V. D. Luong & N. D. Do  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. Thanh Hoa Province, Lang Chanh District, Tri Nang Commune, evergreen forest at an elevation of 800 m, October 2023, Pham Binh Nguyen, Do Ngoc Dai DL231021 (holotype DLU, isotype VAFS).

Description: Shrubs, 3.0–5.0 m tall, young branches glabrous, light brown. Leaves stalked, oblong-elliptic, 16.0–24.0 cm long, 5.0–7.5 cm wide, thickly, coriaceous; apices attenuate, bases obtuse or nearly round, margins shallow serrate; upper sides dark green, shiny, and glabrous; undersides paler green, sparsely pubescent; midribs protruding both sides, lateral veins sunken above, protruding below; secondary venation 12–16 pairs of veins; petioles falcate, slightly curved, round, light purple,1.5–1.9 cm long, glabrous. Flowers 1–2 terminal, nodding, 10.0–11.5 cm in diameter; pedicels 1.0–1.1 cm long, stout, thickened upwards, purple, glabrous; bracteoles 3–4, orbicular or suborbicular, 3.0–6.0 mm long, 4.0–6.0 mm wide, outer surfaces purplish red, inner surfaces purplish green, glabrous, margins membranous and ciliate, persistent. Sepals 5– 6, suborbicular or subglobose, 0.7–2.0 cm long, 1.0–1.5 cm wide; outer surfaces red, pubescent; inner surfaces light yellow with purple, glabrous; margins membranous and ciliate, persistent. Petals 15–16, oblong-obovate, red, 4.5–7.5 cm long, 2.0–3.5 cm wide, outer surfaces pubescent, innermost petals basally united with outermost filaments for 2.0–2.8 cm. Androecium numerous, arranged in five circles, filaments 3.0–5.0 cm long, light pink, sparsely pubescent at the base, outer filaments basally united for 3.0–3.5 mm; anthers ca. 2.0 mm, yellow, dorsifixed. Gynoecium 3–4-locular, ovaries superior, subglobose, 3.0–4.0 mm long, 4.0–5.0 mm wide, tomentose; styles 3–4, free to the base, 3.5–5.2 cm long, sparsely tomentose. Capsules not seen.

Phenology: Flowering from October to December.

Distribution, habitat, and conservation status: Camellia nguyenii has only been found in Tri Nang Commune, Lang Chanh District, Thanh Hoa Province, with fewer than 10 mature individuals in ca. 20 ha. There are many agricultural activities in the area posing a threat to the forest habitat. Due to the limited known area of occupancy and small population size, we consider the IUCN category of Critically Endangered (CR B2ab (iii, v)) to be appropriate for this species.

Etymology: The epithet honors Mr. Pham Binh Nguyen, who discovered this species.

Vernacular name: Trà nguyên.

Additional specimens examined:—VIETNAM. Thanh Hoa Province, Lang Chanh District, Tri Nang Commune, evergreen forest at an elevation of 840 m, November 2024, Ngan Thi Tin DL241102 (DLU).

VIET NAM: Tri Nang Commune, Lang Chanh District, Thanh Hoa Province

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

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

模式标本：越南清化省朗正县知能社，常绿阔叶林，海拔800米，2023年10月，Pham Binh Nguyen 与 Do Ngoc Dai 采集，标本号 DL231021（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：灌木，高3.0–5.0米；幼枝无毛，淡褐色。叶具柄，长椭圆形，长16.0–24.0厘米，宽5.0–7.5厘米，厚革质；先端渐狭，基部钝或近圆形，边缘具浅锯齿；上面深绿色，有光泽，无毛；下面淡绿色，疏生短柔毛；中脉两面突起，侧脉在上面凹陷，在下面突起；二次脉12–16对；叶柄镰刀形，微弯曲，圆形，淡紫色，长1.5–1.9厘米，无毛。花1–2朵顶生，下垂，直径10.0–11.5厘米；花梗长1.0–1.1厘米，粗壮，向上增粗，紫色，无毛；小苞片3–4枚，圆形或近圆形，长3.0–6.0毫米，宽4.0–6.0毫米，外面紫红色，内面紫绿色，无毛，边缘膜质且具缘毛，宿存。萼片5–6枚，近圆形或近球形，长0.7–2.0厘米，宽1.0–1.5厘米；外面红色，被短柔毛；内面淡黄色带紫色，无毛；边缘膜质且具缘毛，宿存。花瓣15–16枚，长圆状倒卵形，红色，长4.5–7.5厘米，宽2.0–3.5厘米，外面被短柔毛，最内层花瓣与最外层花丝基部合生2.0–2.8厘米。雄蕊多数，排列成5轮，花丝长3.0–5.0厘米，淡粉色，基部疏被短柔毛，外层花丝基部合生3.0–3.5毫米；花药长约2.0毫米，黄色，背部着生。雌蕊3–4室，子房上位，近球形，长3.0–4.0毫米，宽4.0–5.0毫米，被绒毛；花柱3–4枚，自基部完全分离，长3.5–5.2厘米，疏被绒毛。蒴果未见。

物候期：花期10月至12月。

分布、生境与保护现状：平元山茶Camellia nguyenii目前仅在清化省朗正县知能社发现，成熟个体数少于10株，分布面积约20公顷。该区域存在大量农业活动，对森林栖息地构成威胁。由于其已知占有面积极其有限且种群数量极小，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“nguyenii”以该物种的发现者范平元（Pham Binh Nguyen）先生的名字命名。

越南语名：Trà nguyên。

其他标本：越南清化省朗正县知能社，常绿阔叶林，海拔840米，2024年11月，Ngan Thi Tin 采集，标本号 DL241102（存于大叻大学标本馆 DLU）。

越南清化省朗正县知能社