文朗山茶 Camellia vanlangensis V.D.Luong & V.T.PhamCamellia vanlangensis

Camellia vanlangensis V.D.Luong & V.T.Pham. First published in Taiwania 68: 465-471 (2023). Type: VIETNAM, Thanh Hoa Province: Lang Chanh District, Giao An Commune, primary closed evergreen broad-leaved mixed with bamboo forest with highly impacted, around point 20°03'23.4"N, 105°14'46.6"E, at elevation 800 m, 26 October 2021, Trinh Ngoc Bon and Pham Binh Nguyen Bon211101 (holotype: DLU; isotype: VAFS); 26 August 2022, Pham Van The and Pham Binh Nguyen PVT1033 (paratype: VAFS).  

The specimen was discovered by Trinh Ngoc Bon, Pham Binh Nguyen in 2021 in Lang Chanh district, Thanh Hoa province. In 2023, the group of authors Trinh Ngoc Bon, Luong Van Dung, Le Nguyet Hai Ninh, and Pham Van The published in the Taiwania magazine with the scientific name Camellia vanlangensis, the Vietnamese name is Tra Van Lang, which is the name of the old national name of Vietnam and also the name of Van Lang University where the author Pham Van The works.

Diagnosis: The new species most differs from Camellia impressinervis Hung T. Chang & S.Ye Liang (1979) with its cordate leaves base (vs. rounded to obtuse), more secondary leaf veins (16–22 vs. 9–11 pairs), longer sepals (3.5–4.3 vs. 0.1–1.0 cm), and larger capsules 4–5 vs. 3 cm. It’s most distinct from C. calcicola T.L.Ming (1993) by its sparse tomentose on leaves (vs. glabrous in adaxial and pubescent in abaxial surfaces), longer sepals (3.5–4.3 vs. 0.9–1.4 cm), glabrous petals and filaments (vs. pubescent), and glabrous ovary and style (vs. pubescent).

Description: Evergreen tree, 5–8 m tall, trunk ca. 15 cm in diam. at base, with sparse and wide canopy, bark dark green with large white-grey patches, young branches ca. 0.5 cm in diam., red, later dark green, sparsely tomentose, terminal buds small, conical, ca. 0.3 cm in diam., outside surface white hirsute. Leaves petioles stout, curved, 15–19 mm long, 4–5 mm in diam., red and hirsute when young, dark green and sparsely tomentose when old, blades thinly leathery, elliptic to oblong-elliptic, 25–33 cm long, 7.5–12.5 cm wide, adaxial surface glabrous, shiny and dark green, abaxial surface pale green, sparsely tomentose, apex acuminate, base cordate, plicate, margin entire to slightly serrulate, slightly revolute, secondary veins not reaching to the margins, distinct on both surfaces, adaxially sunken, abaxially prominent, midrib red and pubescent abaxially when young, yellow-green and sparsely tomentose when old, secondary veins 16–22 pairs. Flower buds bright yellow, elliptic, ca. 3.5 cm long, 2.5 cm in diam. Flowers solitary, subterminal, cup shaped, 5–8 cm in diam., golden yellow, pedicels ca. 1 cm long, 0.3 cm in diam., covered with bracteoles and sepals, glabrous. Bracteoles 5–6, sometimes dried in flower buds stage, persistent, variable in size and shape, suborbicular, deltoid, ovate, broadly elliptic, smallest one ca. 0.6 cm long and 0.7 cm wide, biggest one 3.2 cm long and 1.0 cm wide, dark-green to light green, orange or orange-red, concave, adaxial surface almost glabrous except for base, abaxial surface sparsely tomentulose, base rounded, apex acute, margins ciliate, involute. Sepals 9–10, sometimes dried in flower buds stage, persistent, deltoid, ovate to elliptic, 3.5–4.3 cm long, 1.0 3.0 cm wide, orange-green to orange-red, concave, adaxial surface almost glabrous except for base, abaxial surface sparsely tomentulose, apex acute, margins ciliate, strongly involute. Petals 10–11, orbicular to broadly obovate, 2.8 4.3 cm long, 1.8–3.1 cm wide, glabrous on both sides, united with androecium at 0.8–1.4 cm from the base, shiny, concave, apex round. Androecium glabrous, stamens 130–150, 5 whorls, filaments 25–37 mm long, ca. 0.6 mm in diam., outer ones basally connate into a tube for 19–23 mm long from base, anthers 2.6–4.0 mm long, 1 mm wide, golden yellow. Gynoecium glabrous, yellow, ovary 3–5 loculed, conical, angled, 3.6–4.6 mm long, 4.0–5.5 mm in diam., styles 3–5, free from base, 25–28 mm long. Capsule subglobose, 4–5 cm in diam., surface rough, distinctly 5 rigged, sunken at apex. Seed 1 in each locule, subglobose or globose-trigonous, 2–2.3 cm in diam., more or less smooth, dark brown, glabrous.

Distribution: Camellia vanlangensis was found in a primary evergreen broad leaved mixed with bamboo forest and highly impacted at elevation around 800 m in Lang Chanh and Nhu Xuan Districts, Thanh Hoa Province.

Etymology: The epithet "vanlangensis" refers to an ancient name of Vietnam, Van Lang. Proposed Vietnamese name: Trà hoa vàng Văn Lang 

IUCN Conservation status: Currently, Camellia vanlangensis is known from two populations in Thanh Hoa Province. One of which is in Lang Chanh District where the type specimens were collected. The other one was recorded by local people with video evidence in Nhu Xuan District. Its habitats do not belong to any protected area and are severely fragmented by farming, selected timber cutting, firewood and collecting non timber forest products. It also is seriously threatened by Camellia enthusiasts. Based on the criteria from the IUCN Standards and Petitions Subcommittee (2019), the extent of occurrence (EOO) is less than 1 km2 and the area of occupancy (AOO) is 8,000 km2. This falls under the Critically Endangered (CR) with B1ab(i-iv) + B2ab(i-iv). 

 Lang Chanh and Nhu Xuan Districts, Thanh Hoa Province, Vietnam

文朗山茶 Camellia vanlangensis V.D.Luong & V.T.Pham.Taiwania 68: 466 (2023).

该标本由 Trinh Ngoc Bon 和 Pham Binh Nguyen 于 2021 年在清化省 Lang Chanh 县发现。2023 年，由 Trinh Ngoc Bon、Luong Van Dung、Le Nguyet Hai Ninh 和 Pham Van The 组成的作者小组在《Taiwania》杂志上发表了学名为 Camellia vanlangensis 的文章，越南语名称为 Tra Van Lang，这是越南的旧国名文朗（Van Language），也是作者 Pham Van The 工作的 Van Lang 大学的校名。

常绿乔木，高5-8米，树干基部直径约15厘米，树冠稀疏而宽大，树皮深绿色，有大块白色灰色斑块，幼枝直径约0.5厘米，红色，后变为深绿色，疏生绒毛，顶芽小，圆锥形，直径约0.3厘米，外表面有白色长硬毛。叶柄粗壮，弯曲，长 15-19 毫米，直径 4-5 毫米、 叶片薄革质，椭圆形至长圆状椭圆形，长25-33厘米，宽7.5-12. 5厘米宽，正面无毛，有光泽，深绿色，背面淡绿色，疏生绒毛，先端渐尖，基部心形，折扇状，边缘全缘至稍有细锯齿，稍外卷，次脉不达边缘，两面明显，正面凹陷，背面突出，中脉幼时红色，背面有短柔毛，老时黄绿色，疏生绒毛，次脉16-22对。花芽鲜黄，椭圆形，长约 3.5 厘米，直径约 2.5 厘米。花单生，近顶生，杯状，直径 5-8 厘米，金黄色，花梗长约 1 厘米，直径 0.3 厘米，被小苞片和萼片覆盖，无毛。小苞片 5-6 个，有时在花蕾期就干了，宿存，大小和形状不一，近圆形、正三角形、卵形、宽椭圆形，最小的一个长约 0.6 厘米，宽约 0.5 厘米。长 0.6 厘米、宽 0.7 厘米，最大的长 3.2 厘米、宽 1.0 厘米，深绿色至淡绿色，橙色或橙红色，凹陷，正面除基部外几乎无毛，背面疏生被微绒毛，基部圆形，先端锐尖，边缘具缘毛，内卷。萼片9-10，有时在花芽期干燥，宿存，正三角形，卵形到椭圆形，长3.5-4.3厘米，宽1.0-3.0厘米，橙绿到橙红色，凹面，正面除基部外几乎无毛，背面疏被微绒毛，先端锐尖，边缘具缘毛，强烈内卷。花瓣10-11，圆形至宽倒卵形，长2.8-4.3厘米，宽1.8-3.1厘米，两面无毛，在距基部0.8-1.4厘米处与雄蕊群结合，有光泽，凹，先端圆形。雄蕊群无毛，雄蕊 130-150 枚，5 轮，花丝长 25-37 毫米，直径约 0.6 毫米，外侧花丝基部合生成筒状，自基部起长 19-23 毫米，花药长 2.6-4.0 毫米，宽 1 毫米，金黄色。雌蕊群无毛，黄色，子房3-5室，圆锥形，有棱，长3.6-4.6毫米，直径4.0-5.5毫米，花柱3-5，离生，长25-28毫米。蒴果近球形，直径4-5厘米，表面粗糙，明显5棱形，先端凹陷。种子1粒，近球形或球状三棱，直径2-2.3厘米，或多或少光滑，暗褐色，无毛。

分布： 文朗山茶（Camellia vanlangensis）生长在清化省Lang Chanh县和Nhu Xuan县海拔800米左右的原始常绿阔叶林与竹林混交地带。

词源： 种加词 “vanlangensis ”指的是越南国名的一个古老名称 Van Lang。拟用越南语名称：Trà hoa vàng Văn Lang 

越南清化省Lang Chanh县和Nhu Xuan县