文协山茶 Camellia hiepii V.S.Dang, Vuong, V.C.Nguyen & V.D.LuongCamellia hiepii

Camellia hiepii V.S.Dang, Vuong, V.C.Nguyen & V.D.Luong. First published in Kew Bull. 78: 359 (2023).

The specimen was first discovered by Nguyen Van Canh in 2020 at Chu Mu Mountain, M' Drak District, Dak Lak Province. In 2023, the authors Nguyen Thi Lien Thuong, Nguyen Van Canh, Truong Quang Cuong, Nguyen Van Khuong, Luong Van Dung, Truong Ba Vuong, and Dang Van Son published in Kew Bulletin under the scientific name Camellia hiepii. The Vietnamese name is Tra Hiep, named after Mr. Nguyen Van Hiep, former chairman of the Board of Trustees of Thu Dau Mot University. This is one of the camellia species with the largest leaves, reaching up to 80 cm.

Camellia hiepii V.S.Dang, Vuong, V.C.Nguyen & V.D.Luong sp. nov. Type: Vietnam, Dak Lak Province, M'Drak Distr., Chu Mu mountains, along streams composed of sandstone in evergreen forests, at 500 – 800 m elevation, 20 Dec. 2020, Van Canh Nguyen, Quang Cuong Truong & Van Dung Luong DLU201220 (holotype DLU!; isotypes DLU!, VNM!).

Shrub or small tree, 2 ‒ 8 m tall; young branches sparsely pubescent then glabrous when aging, dark-green; adult branches light brown, slightly corky, smooth with lighter-coloured patches; terminal buds short, roughly triangular, 1 – 2.5 mm long, pubescent, apex acute. Leaves alternate, blades narrow elliptic to oblong, 22 ‒ 80 × 9 ‒ 18 cm, coriaceous, adaxially dark green, shiny and glabrous, abaxially pale green, sparsely pubescent, apex acute or obtuse, base subcordate or cordate, margin sunken; midrib slightly adaxially, prominent abaxially; secondary veins 17 – 20 pairs, ascending at an angle of 50 – 65° from the midrib, curved to the margin, sunken adaxially, distinct abaxially; tertiary veins subparallel; petioles falcate, slightly curved, 1 ‒ 1.5 cm long, light green or yellowish to mid-green, sparsely pubescent. Flowers pedunculate, usually solitary, sometimes growing in groups of 2 flowers borne at the ends of the shoots, axillary, nodding, 8 ‒ 9 cm diam.; pedicel stout, 1 ‒ 1.2 cm long, dark pink, glabrous; bracteoles 2, scales or suborbicular, 2.5 ‒ 4 × 3 ‒ 3.5 mm, light red, abaxially pubescent, adaxially glabrous, persistent; sepals persistent, orbicular or subglobose, 0.5 – 1.4 × 01 – 1.8 cm, abaxially red and pubescent, adaxially pale reddish and glabrous, margins ciliate; petals 11 ‒ 12, red to dark red, arranged in 2 whorls, outermost 5, broad obovate, 3.5 ‒ 5.2 × 2.7 ‒ 4.3 cm, abaxially pubescent, adaxially glabrous over the whole surface or the middle towards the apex; innermost 6 ‒ 7, broad oval, 5 ‒ 5.5 × 3 ‒ 4.4 cm, abaxially pubescent in the middle towards the apex, adaxially glabrous, basally united with filaments 1 ‒ 1.2 cm long at base; androecium numerous, stamens in 5 ‒ 6 circles, reddish-pink, 3 ‒ 3.5 cm long, glabrous, outer filaments united for 1.4 ‒ 1.5 cm at base; anthers small, 1.5 ‒ 2 × 1 ‒ 1.5 mm, light yellow; gynoecium superior, 5 or 6-locular, flattened globose, 18 ‒ 19 ribbed, 3 ‒ 3.5 × 4.5 ‒ 5 mm, tomentose; styles 5 ‒ 6, free at the base, 3.2 ‒ 3.5 cm long. Capsules flattened globose, 2.1 ‒ 2.4 × 5 ‒ 5.5 cm, glabrous, dehiscing into 5 ‒ 6 (‒ 8) parts; pericarp 1 ‒ 1.5 mm thick, sparsely hairy, 1 ‒ 2 seeds per locule; columella stout, 1.2 ‒ 1.3 cm long. Seeds semi-globose or cuneate, 2.1 ‒ 2.4 × 1.2 ‒ 1.4 cm, shining brown, glabrous. Figs 1, 2, 3 and 4.recognition. 

Camellia hiepii is most similar to C. longii Orel & Luu in leaf morphology and red petals, but differs from the latter by having sparse pubescence on young branches (vs glabrous), larger leaf blades (22 ‒ 80 × 9 ‒ 18 cm vs 27 – 31 × 6 – 9 cm), more secondary veins (17 – 20 pairs vs 14 – 16 pairs), flower 8 ‒ 9 cm in diam. (vs 3.5 ‒ 5 cm in diam.), petals 11 ‒ 12 and broad obovate (vs 5 – 6 and campanulate), longer stamens (3 ‒ 3.5 cm vs 1.5 – 1.8 cm) and shorter styles (3.2 ‒ 3.5 cm vs 4.5 – 4.7 cm).

Distribution. Camellia hiepii is endemic to Vietnam. Currently known from Chu Mu mountains, M'Drak Distr., Daklak Province, the Central Highlands of Vietnam.habitat. Camellia hiepii is currently found only in its type locality at 500 – 800 m elevation. This species grows along streams or under the shade of evergreen forests on moist fertile and sandy soils.

IUCN. Camellia hiepii is so far only known from Chu Mu mountains, M'Drak Distr., Daklak Province, the Central Highlands of Vietnam. It was collected in a single population containing less than 200 individuals. The Extent of Occurrence (EOO) is less than 100 km2 and the known Area of Occupancy (AOO) is less than 30 km2. Therefore, we propose a status of Endangered (EN - B1ab(iii)) based on the IUCN Red List Categories and Criteria (IUCN 2022).

Phenology. Flowering from December to March of the following year, fruiting from April to July.

Etymology. The specific epithet of this species honours Assoc. Dr Nguyen Van Hiep, Chairman of the Management Board of Thu Dau Mot University, who supported the survey in the Central Highlands of Vietnam.vernacular name. Trà Hiệp.notes. 

Camellia hiepii is also similar to C. honbaensis Luu, Q.D.Nguyen & G.Tran, C. piquetiana (Pierre) Sealy and C. phuongchiana Curry, V.H.Quach, T.T.Hoang & T.Q.Cuong, which are endemic to Vietnam but differ from them in several characteristics (see Table 1).

Vietnam

文协山茶 Camellia hiepii V.S.Dang, Vuong, V.C.Nguyen & V.D.Luong

该标本由 Nguyen Van Canh 于 2020 年在达乐省 M'Drak 县 Chu Mu 山首次发现。2023 年，作者 Nguyen Thi Lien Thuong、Nguyen Van Canh、Truong Quang Cuong、Nguyen Van Khuong、Luong Van Dung、Truong Ba Vuong 和 Dang Van Son 在Kew Bulletin上发表，学名为 Camellia hiepii。越南语名称为 Tra Hiep，以 Thu Dau Mot 大学前董事会主席 阮文协(Nguyen Van Hiep) 先生的名字命名。这是叶片最大的茶树品种之一，可达 80 厘米。

Camellia hiepii V.S.Dang, Vuong, V.C.Nguyen & V.D.Luong sp. 模式： 20 Dec. 2020, Van Canh Nguyen, Quang Cuong Truong & Van Dung Luong DLU201220 (holotype DLU!; isotypes DLU!, VNM!).

灌木或小乔木，高 2 - 8 米；幼枝疏生短柔毛，老时无毛，深绿色；成枝淡褐色，稍木栓化，光滑，有浅色斑块；顶芽短，大致三角形，长 1 - 2.5 毫米，被短柔毛，先端锐尖。叶互生，叶片狭椭圆形至长圆形， 22 - 80 * 9 - 18 厘米，革质，正面深绿色，发亮无毛，背面苍绿色，疏生短柔毛，先端锐尖或钝，基部近心形或心形，边缘凹陷； 中脉稍正面，背面突出；次脉 17 - 20 对，与中脉呈 50 - 65° 角上升，向边缘弯曲，正面凹陷，背面明显；支脉近平行；叶柄镰刀形，稍弯曲，长 1 - 1. 5 厘米长，淡绿色或淡黄色至中绿色，疏生短柔毛。花有花序梗，通常单生，有时2朵成群，生于嫩枝末端，腋生，有节，直径8 - 9厘米；花梗粗壮，长1 - 1.2厘米，深粉红色，无毛；小苞片2，鳞片状或近圆形， 2.5 - 4 * 3 - 3. 5 毫米，淡红色，背面具短柔毛，正面无毛，宿存；萼片宿存，圆形或近球形， 0.5 - 1.4 * 01 - 1.8 厘米，背面红色和短柔毛，正面淡红色和无毛，边缘具缘毛；花瓣 11 - 12，红色至暗红色，排列成 2 轮，最外层 5，宽倒卵形， 3.5 - 5.2 * 2.7 - 4. 3厘米，背面具短柔毛，正面全缘或中部向先端无毛；最里面的6 - 7，宽椭圆形， 5 - 5.5 × 3 - 4.4厘米，中部向先端具短柔毛，正面无毛，基部合生花丝长1 - 1.2厘米；雄蕊群多数，雄蕊5 - 6圈，红粉色，长3 - 3. 5 厘米长，无毛，外花丝基部合生 1.4 - 1.5 厘米；花药小， 1.5 - 2 * 1 - 1.5 毫米，浅黄色；雌蕊群上位，5 或 6 室，扁球形，18 - 19 棱， 3 - 3.5 * 4.5 - 5 毫米，被绒毛；花柱 5 - 6，基部离生，3.2 - 3.5 厘米长。蒴果扁球形， 2.1 - 2.4 * 5 - 5.5 厘米，无毛，开裂成 5 - 6（- 8）部分；果皮厚 1 - 1.5 毫米，疏生毛，每室 1 - 2 粒种子；轴柱粗壮，长 1.2 - 1.3 厘米。种子半球形或楔形， 2.1 - 2.4 * 1.2 - 1.4 厘米，棕色发亮，无毛。图 1、2、3 和 4。与C. longii Orel & Luu 最相似，但与后者的不同之处在于幼枝上有稀疏的短柔毛（vs 无毛），叶片较大（22 - 80 × 9 - 18 厘米 vs 27 - 31 × 6 - 9 厘米），次脉较多（17 - 20 对 vs 14 - 16 对），花直径为 8 - 9 厘米（vs 3.5 - 5 厘米）。(花瓣 11 - 12，宽倒卵形（5 - 6，钟状），雄蕊长（3 - 3.5 厘米 vs 1.5 - 1.8 厘米），花柱短（3.2 - 3.5 厘米 vs 4.5 - 4.7 厘米）。

分布 阮文协山茶（Camellia hiepii）是越南特有的植物。目前产于越南中央高原达克拉克省M'Drak Distr.的Chu Mu山区。Camellia hiepii 目前仅见于海拔 500 - 800 米的模式产地。该物种生长在潮湿肥沃的沙质土壤上的溪流边或常绿林的树荫下。

IUCN。阮文协山茶（Camellia hiepii）目前仅产于越南中部高原达克拉克省（Daklak Province）M'Drak Distr.的Chu Mu山区。它是在一个包含不到 200 个个体的单一种群中采集到的。其分布范围（EOO）小于 100 平方公里，已知栖息地（AOO）小于 30 平方公里。因此，根据世界自然保护联盟红色名录的类别和标准（IUCN 2022），我们建议将其列为濒危物种（EN - B1ab(iii)）。

花期 12月至翌年3月开花，4月至7月结果。

词源 该物种的特称是为了纪念 Thu Dau Mot 大学管理委员会主席 Nguyen Van Hiep 副博士，他支持了越南中央高地的调查。

注释 Camellia hiepii 与越南特有的 C. honbaensis Luu, Q.D.Nguyen & G.Tran, C. piquetiana (Pierre) Sealy 和 C. phuongchiana Curry, V.H.Quach, T.T.Hoang & T.Q.Cuong 相似，但在一些特征上有所不同。

越南中央高原达克拉克省