越南中部山茶 Camellia annamensis N.S.Lý, V.D.Luong, N.D.Do, T.H.Lê & Thi L.NguyenCamellia annamensis

Camellia annamensis N.S.Lý, V.D.Luong, N.D.Do, T.H.Lê & Thi L.Nguyen in Taiwania 67: 244 (2022)

The species was discovered by Luong Van Dung, Nguyen Thi Lieu, Do Cong Thuan, Tran Ninh, Chiyomi Uematsu and Hironori Katayama in December 2016 in Yen Nhan commune, Thuong Xuan district, Thanh Hoa province (Xuan Lien Nature Reserve). The authors Do Ngoc Dai, Ly Ngoc Sam, Le Thi Huong, Nguyen Danh Hung also discovered the species in 2019 in Dong Van commune, Que Phong district, Nghe An province. In 2022, the authors Ly Ngoc Sam, Luong Van Dung, Le Thi Huong, Do Ngoc Dai, Tran Ninh, Nguyen Anh Duc, Nguyen Thi Lieu,  Chiyomi Uematsu and Hironori Katayama published in the Taiwania No. 67 under the scientific name Camellia annamensis. The Vietnamese name means Central Camellia, which has only been recorded in the world to be distributed in Thanh Hoa and Nghe An of Vietnam.

Type: VIETNAM. Nghệ An Province: Quế Phong District, Đồng Văn Commune, Pù Hoạt NR, 240 m elev.,15 January 2019, Đỗ Ngọc Đài, Lý Ngọc Sâm, Lê Thị Hương, Nguyễn Danh Hùng, DLHH-1028 (holotype VNM!; isotypes P!, DLU!).

Description: Small to medium evergreen shrub 3‒5 m tall, sometime multi-stemmed, semi-upright habit, sparsely branched, branches slender; young branches (twigs) light brown, smooth, hirsute then glabrous, obliquely upward then flexuous; semi-mature branches cinnamon brown, smooth, leaf scars prominent; mature branches and trunk light grey to dull grey-white, with longitudinally fissured bark/slightly furrowed. Leaf buds pale greenish then turning pale brown, puberulous, slightly falcate with sharp, slightly curved apex; young leaves soft and pendulous, pale purple to greenish-purple tinted; mature leaves elliptic to broad elliptic, 15‒20.5 × 5‒9 cm, apex attenuate or narrowly acuminate, base acute to partially obtuse and slightly asymmetric, margin shallowly and widely denticulate; laminae coriaceous, adaxially dark green, shiny and glabrous, abaxially dull and pale green with sparsely appressed puberulous; petiole curved and concave, slightly flattened, thick, light green both sides, 10‒15 × 2‒2.5 mm, sparsely appressed puberulous; primary veins [partially obstructed by laminae abaxially] continues as a shallow channel on the adaxial side of the petiole, 1.5–1.7 mm wide proximally, less than 1 mm wide distally, adaxially light green, abaxially yellowish-green; secondary venations pinnate, with 10‒13 pairs of veins, indistinctly brochidodromous, partially eucamptodromous on some leaves; midribs and lateral veins sunken above, protruding below; veins distinct proximally but less so towards the apex and the margins; tertiary venation loose, inconspicuous craspedodromous, more prominent at leaf margins. Flowers solitary or geminate (2(‒3) flowers), born on short shoot in the axils of the leaves, 4.5‒6 cm in diameter, flowers pedicellate, nodding; pedicels 0.7‒1 cm long, 0.3‒0.4 cm wide, wider distally, glabrous, pale greenishcream [pale yellowish]; flower buds slightly curved downward, somewhat circular/globe, ca. 1.4 × 1.5 cm, bright red. Bractlets 3‒4, broad triangular to semiorbicular, 1.5‒2.5 × 2‒3 mm, glabrous, margins ciliate, persistent. Sepals 5, persistent, semi-orbicular, 4‒8 × 6‒ 10 mm, abaxially pale yellow tinged reddish and sparsely appressed velutinous, adaxially pale yellow and glabrous, margins entire/ciliate, arranged in 2 whorls forming a rather loose spiral, outer whorl of 2 sepals and inner whorl of 3 sepals. Petals 20‒22, arranged in 3 whorls, bright red, shiny, with a distinct and intense white margin 1.5–2 mm wide; outermost whorl comprising 7–8 petals, semiorbicular, 1.5–2.4 × 1.2–1.8 cm, concave, margins entire, sometimes ruffled, abaxially velutinous at tips; middle whorl comprising 11 petals, broadly obovate, 2.7–3.7 × 2–2.5 cm, concave, margins ruffled, abaxially pubescent at tips or glabrous; innermost whorl of 2–3 petals, elliptic, 3.3–3.5 × 1.3–2.2 cm, glabrous, ruffes, basally united with outermost filaments for 5–10 mm. Androecium ca. 350 stamens, arranged in 4 or 5 series, light yellow, 2.4‒ 3 cm long, glabrous; outer filaments basally united to each other for 1.5–1.8 cm long and forming a cup, inner ones basally united for 4–7 mm long; anthers yellow, narrowly ovate, 2.5–3 × ca. 1 mm, with two longitudinal striations, dorsifixed. Ovaries superior, flattened-globose, terminating into 4 or 5 styles, strongly 4‒5-lobed, yellow, tomentose, 4‒5-carpellate, 2.5‒3 × 3‒3.5 mm, 1‒2 ovules per locule. Styles 4 or 5, free to the base, 1.8‒2.3 cm long, 0.5–0.7 mm wide at base, ca. 0.5 mm at apex, yellow, tomentose, persistent; stigma indistinct. Mature Capsules flattened-globose, with persistent sepals and styles, 4‒5 irregularly lobed, 4‒5.5 cm in diam., 2‒2.3 cm high, dehiscing distally into 4‒5 valves with 1‒2 seeds per valve; fresh pericarps 3‒4 mm thick, furfuraceous and sparsely white hairs. Seeds spherical, hemispherical or wedgeshaped, 1.6–1.8 × 1.2–1.5 cm, brown, pubescent.

Distribution and ecology: This new species is found from two localities in the provinces of Nghệ An and Thanh Hóa in central Vietnam where it grows along the sides of the stream, wet ground or on hill slopes in mixed tropical secondary evergreen broad-leaved forests in Pù Hoạt NR at elevations of 260–600 m and Xuân Liên NR at an elevation of around 500 m. The two localities are distanced about 30 km.

According to Ly et al. (2022), C. annamensis was placed under sect.Piquetia. This species is most similar to C. longii Orel & Luu in the characters of general vegetative habit and the shape and color of sepals, petals, and stamens. It is easily distinguishable from C. longii by its mature leaves sparsely appressed puberulous abaxially, petioles sparsely appressed puberulous (vs. glabrous), sepals 5 (vs. 2–3), and petals 20‒22 (vs. 5‒6). Camellia annamensis is also similar to C. dalatensis, C. sonthaiensis, and C. proensis but is easily distinguished from them by having red flowers (vs. light-yellow flowers in the other three species).

VIETNAM: Nghệ An province and Thanh Hóa province

越南中部山茶 Camellia annamensis。与长叶山茶（Camellia longii）最为相似，但不同之处在于其成熟叶片背面稀疏贴伏微柔毛，叶缘具浅而宽的小齿，侧脉 10-13 对，叶柄稀疏贴伏微柔毛，萼片 5，花瓣 20-22 ，子房扁球形，花柱被绒毛且离生至基部。

小到中型常绿灌木，高 3-5 米，有时多茎，半直立习性，分枝稀少，枝条纤细；幼枝（小枝）淡褐色，光滑，先具长硬毛后无毛，先斜向上后曲折；半成熟枝肉桂棕色，光滑，叶痕突出；成熟枝和树干浅灰色至暗灰白色，树皮纵向开裂/略有皱褶。叶芽淡绿色，然后变为淡褐色，被微柔毛，稍镰刀形，先端尖锐，稍弯曲；幼叶柔软下垂，淡紫到绿紫色；成熟叶椭圆形到宽椭圆形, 15-20.5 x 5-9 厘米，先端渐狭或狭渐尖，基部锐尖到部分钝，稍不对称，边缘具浅而宽的小齿；叶片革质，正面深绿色，发亮无毛，背面暗淡苍绿色，有稀疏贴伏微柔毛；叶柄弯曲凹陷，稍扁平，厚，两面淡绿色,10-15 x 2-2.5 毫米，疏生贴伏微柔毛；主脉 [背面部分被叶片阻挡] 在叶柄正面延续为一条浅沟。下部宽1.5-1.7毫米，上部宽不到1毫米，正面淡绿色，背面黄绿色；羽状次脉，有10-13对脉，不明显有帚状脉，有些叶片上有部分帚状脉；中脉和侧脉在上面凹陷，在下面突出；下部脉明显，但向先端和边缘较少；第三脉松散，不明显有嵴状脉，在叶缘较突出。花单生或总状花序（2(-3)朵花），生于叶腋的短枝上，直径 4.5-6 厘米，花有花梗，有节；花梗长 0.7-1 厘米，宽 0.3-0.4 厘米，上部较宽，无毛，淡绿乳白色 [淡黄色]；花蕾稍向下弯曲，有点圆/球形，长约 1.4 × 1.5 厘米，鲜红色。小苞片 3-4 ，宽三角形到半圆形， 1.5-2.5 x 2-3 毫米，无毛，边缘具缘毛，宿存。萼片 5，宿存，半圆形， 4-8 x 6-10 毫米，背面淡黄色微染带红色和稀疏贴伏短绒毛，正面淡黄色无毛，边缘全缘/具缘毛，排列成 2 轮，形成相当松散的螺旋形，外轮 2 枚萼片，内轮 3 枚萼片。花瓣 20-22 片，排列成 3 轮，鲜红色，有光泽，有明显而强烈的白色边缘，宽 1.5-2 毫米；最外轮由 7-8 片花瓣组成，半圆形， 1.5-2.4 x 1.2-1.8 厘米，凹陷，边缘全缘，有时皱褶，顶端背面具短绒毛；中轮由 11 片花瓣组成，宽倒卵形, 2.7-3.7 x 2-2.5 厘米，凹，边缘具荷叶边，背面具短柔毛在顶部或无毛；最内轮2-3瓣，椭圆形， 3.3-3.5 x1.3-2.2 厘米，无毛，具荷叶边，基部与最外轮花丝合生达5-10毫米。雄蕊群约 350 个，排列成 4 或 5 列，淡黄色，长 2.4-3 厘米，无毛；外花丝基部互相连接，长 1.5-1.8 厘米，形成杯状，内花丝基部连接，长 4-7 毫米；花药黄色，狭卵形， 长约2.5-3.1 毫米，有两条纵纹，背着。子房上位，扁平球形，顶生 4 或 5 个花柱，强烈 4-5 裂，黄色，被绒毛，4-5 具心皮， 2.5-3 X 3-3.5 毫米，每室 1-2 胚珠。花柱4或5，离生至基部，长1.8-2.3厘米，基部宽0.5-0.7毫米，先端长约0.5毫米，黄色，被绒毛，宿存；柱头不清楚。成熟的蒴果扁球形，有宿存的萼片和花柱，4-5枚不规则浅裂，直径4-5.5厘米，高2-2.3厘米，上部开裂成4-5裂爿、每裂爿有1-2枚种子；新鲜的果皮厚3-4毫米，有软鳞片和稀疏的白色毛。种子球形、半球形或楔形， 1.6-1.8 x 1.2-1.5 厘米，棕色，具短柔毛。

分布与生态： 该新种分布于越南中部义安省和清化省的两个地方，生长在海拔 260-600 米的 Pù Hoạt NR 和海拔 500 米左右的 Xuân Liên NR 热带次生常绿阔叶混交林的溪流边、潮湿地面或山坡上。

该物种由 Luong Van Dung、Nguyen Thi Lieu、Do Cong Thuan、Tran Ninh、Chiyomi Uematsu 和 Hironori Katayama 于 2016 年 12 月在清化省顺宣县延年乡（宣连自然保护区）发现。Do Ngoc Dai、Ly Ngoc Sam、Le Thi Huong和Nguyen Danh Hung 也于 2019 年在义安省 Que Phong 县 Dong Van 乡发现了该物种。2022 年，作者 Ly Ngoc Sam、Luong Van Dung、Le Thi Huong、Do Ngoc Dai、Tran Ninh、Nguyen Anh Duc、Nguyen Thi Lieu、Chiyomi Uematsu 和 Hironori Katayama 在Taiwania 67: 244 (2022)上发表了新种，学名为 Camellia annamensis 。越南语名称的意思是中部山茶，世界上仅有分布于越南清化和义安的记录。

越南中部d的义安省和清化省