玉琼山茶 Camellia quynhii V.D.Luong, V.H.Quach & T.T.HoangCamellia quynhii

Camellia quynhii V.D.Luong, V.H.Quach & T.T.Hoang. First published in Dalat Univ. J. Sci. 12(3): 4 (2022）

The specimen was first discovered by Nguyen Ngoc Quynh in 2019 in Vu Bon commune, Krong Park district, Dak Lak province. In 2020, Quach Van Hoi, Hoang Thanh Truong, and Luong Van Dung collected fruit samples in the above area. In 2022, the group of authors Quach Van Hoi, Hoang Thanh Truong, Luong Van Dung, Nong Van Duy, Bui Danh Chung, and Roman V. Doudkin published in the Dalat University Journal of Science with the scientific name Camellia quynhii, the Vietnamese name is Tra quynh, after the name of the first person to discover the species. The name of species epithet was to honor the first discover person.

Type Vietnam, Dak Lak Province, Krong Pak District, Vu Bon Commune, 12th village, around point 12°35'48.9"N, 108°27'01.0"E, evergreen broadleaf forest on mountain slopes with basaltic red soil, elevation 550–600 m, 01 Jan. 2020, Quach Van Hoi, Hoang Thanh Truong, Luong Van Dung, DL 201101 (holotype, isotype DLU).

Shrub or small evergreen tree, 2–4 m high; young branches brownish, sparsely pubescent and becoming glabrous. Leaves stalked; blades elliptic or broad elliptic, 14-20(–22.5) cm long, 9–12 cm wide, blades thick and coriaceous, glabrous, apex obtuse or shortly acute, margins serrate, base rounded or cordate, shining and deep green above, light green below; lateral veins 7–10 pairs, sunken above and protruding below; petioles stout, curved, 0.8–1.0 cm long, glabrous. Flowers light yellow, almost sessile, solitary (rarely two), terminal, upward, 6.0–7.5 cm in diameter. Bracteoles 2–4, opposite, triangular, 3.0–11 mm long, 3.0–4.0 mm wide, pubescent on both surfaces, persistent. Sepals 6–7, scale or nearly rounded, 0.5–1.2 cm long, 0.5–1.5 cm wide, pubescent on both surfaces, persistent. Petals 12–15, suborbicular to broad elliptic, in three whorls, first whorl 5–6, suborbicular to broad elliptic, 1.0–3.7 cm long, 1.7–2.7 cm wide, pubescent on both surfaces; second whorl 5–6, broad elliptic, 4.0–4.4 cm long, 2.3 2.7 cm wide, pubescent on both surfaces; third whorl 2–3, broad elliptic, 4.5–4.1 cm long, 1.7–2.0 cm wide. Androecium 2.5–3.2 cm long, stamens numerous, in 5–6 whorls, outer filaments united 0.9–1.2 cm, tomentose at the base. Gynoecium 3(–4) locular, ovary ovate, ribbed, 4–5 mm long, 4–4.5 mm wide, glabrous; style 3(–4), 2.7–3.1 cm long, united 1/5 or 1/6 of length from the base, glabrous. Capsule ovoid, 5–5.6 cm high, 4.0–4.5 cm diameter, 3(–4) locular, 2–6 seeds in each loculus, furfuraceous, pericarp 4 5 mm thick, columella 2–2.3 cm high. Seeds rounded on the back and wedge-shaped on the face, 1.4–1.6 cm long, 0.9–1.2 cm wide, dark brown, pubescent.

Phenology Camellia quynhii flowers from November to January of the following year and fruits from June to September.

Distribution and ecology The distribution of this species is known only from one mountain in 12th village, Vu Bon Commune, Krong Pak District, Dak Lak Province. It is located on mountain slopes in evergreen broadleaf forests along the boundaries between plantations and forest.

Conservation status It is estimated that fewer than 200 individuals of C. quynhii are known from only one population that occupies an area of less than 1 hectare. The location is currently threatened by deforestation and agricultural expansion. Therefore, C. quynhii can be assessed as critically endangered (CR) according to IUCN categories and criteria (IUCN, 2019).

Etymology The specific epithet of this species honors Mr. Nguyen Ngoc Quynh, a local person who discovered this species.

玉琼山茶 Camellia quynhii V.D.Luong, V.H.Quach & T.T.Hoang

该标本由阮玉琼（Nguyen Ngoc Quynh） 于 2019 年在达乐省 Krong Park 县 Vu Bon 乡首次发现。2020 年，Quach Van Hoi、Hoang Thanh Truong 和 Luong Van Dung 在上述地区采集了果实样本。2022 年，由 Quach Van Hoi、Hoang Thanh Truong、Luong Van Dung、Nong Van Duy、Bui Danh Chung 和 Roman V. Doudkin 组成的作者小组在《达叻大学科学杂志》上发表了学名为 Camellia quynhii 的论文。种加词为纪念首个发现者。

灌木或常绿小乔木，高2-4米；幼枝带褐色，疏生短柔毛，后渐无毛。叶有柄；叶片椭圆形或宽椭圆形，长14-20（-22.5）厘米，宽9-12厘米，叶片厚而具革质，无毛，先端钝或短锐尖，边缘有锯齿，基部圆形或心形，上面光亮而深绿色，下面淡绿色；侧脉7-10对，上面凹陷，下面突出；叶柄粗壮，弯曲，长0.8-1.0厘米，无毛。花淡黄色，几乎无梗，单生（很少两朵），顶生，向上，直径 6.0-7.5 厘米。小苞片2-4，对生，三角形，长3.0-11毫米，宽3.0-4.0毫米，两面被短柔毛，宿存。萼片6-7，鳞片状或近圆形，长0.5-1.2厘米，宽0.5-1.5厘米，两面被短柔毛，宿存。花瓣12-15，近圆形至宽椭圆形，三轮，第一轮5-6，近圆形至宽椭圆形，长1.0-3.7厘米，宽1.7-2.5厘米，两面被短柔毛，宿存。 第一轮5-6个，近圆形到宽椭圆形，长1.0-3.7厘米，宽1.7-2.0厘米，两面被短柔毛；第二轮5-6个，宽椭圆形，长4.0-4.4厘米，宽2.3-2.7厘米，两面被短柔毛；第三轮2-3个，宽椭圆形，长4.5-4.1厘米，宽1.7-2.0厘米。雄蕊群长 2.5-3.2 厘米，雄蕊多数，5-6 轮，外花丝合生 0.9-1.2 厘米，基部被绒毛。雌蕊群3(-4)室，子房卵形，有棱，长4-5毫米，宽4-4.5毫米，无毛；花柱3(-4)，长2.7-3.1厘米，从基部合生长度的1/5或1/6，无毛。蒴果卵球形，高5-5.6厘米，直径4.0-4.5厘米，3(-4)室，每室2-6粒种子，软鳞片状，果皮厚4.5毫米，轴柱高2-2.3厘米。种子背面圆形，正面楔形，长 1.4-1.6 厘米，宽 0.9-1.2 厘米，黑褐色，被短柔毛。花期：11 月至翌年 1 月，果期： 6 月至 9 月。