红花长柄茶 Camellia zhaiana S.X. YangCamellia zhaiana

Camellia zhaiana S.X. Yang in Phytotaxa 460: 225 (2020).

Type: CHINA. Guangxi: Long’an County, Qiaojian Town, on limestone in the evergreen broad-leaved forest, elev. 30−100m, 16 January 2020, S. X. Yang & P. M. Ye 6324 (holotype KUN, barcodes 1482785; isotypes KUN, PE, K)

Diagnosis: Camellia zhaiana is morphologically similar to C. longipedicellata (Hu 1965: 141) Hung T. Chang & D.Fang in Fang & Chen (1980: 229), but differs in its pink (not white) petals and puberulent (not glabrous) on both petalssurfaces, as well as larger 7.0–10.0 (–13.0) × 3.0–4.0 cm (not smaller 4.0–7.0 × 1.5–3.5 cm) leaves.

Description: Shrub, 2.0−4.0 m tall. Young branches cylindrical, purple-brown, sparsely puberulent and soon glabrous; terminal buds sparsely puberulent. Leaf-blade thinly leathery, elliptic to oblong, 7.0−10 (−13.0) x 3.0−4.0 cm, apex acuminate to caudate, base cuneate or wide cuneate, margin shallow rounded teeth, adaxial surface dark green and glabrous, abaxial surface yellow-green, scattered dark brown glandular spots, glabrous, midvein adaxially sunken and abaxially elevated, secondary veins 6 or 7 on each side of midvein, adaxially slightly impressed and abaxially raised , tertiary venation very indistinct adaxial and visible abaxial; petiole 2.0−4.0 mm long, glabrous. Flowers terminal, solitary, pendulous, 4.0 (−6.0) cm in diam; pedicel slender, yellow-green, 1.5 cm long, apically thickened, glabrous; bracteoles 4 (−6), yellow-green, ovate to broadly ovate, 1.0 x 1.0 mm to 2.0 x 3.0 mm, glabrous, margin ciliate, persistent; sepals 5(−8), yellow-green, 3.0 x 5.0 mm to 7.0 x 10.0 mm, broadly ovate to reniform, glabrous, margin ciliate; petals 14−16 in 4−5 whorls, slightly twisted pubescent on both sides, outermost whorl 1.0 x 1.0 cm, round, sepaloid, innermost whorl 2.0 x 2.0 cm, sub-round to short elliptic, basally connate for 5.0−7.0 mm.Stamens numerous, ca. 2.0 cm long, outer filaments basally connate ca. 2/3 into a tube, pubescent, inner filaments distinct, pubescent to 2/3 from the base; ovary 3-loculed, globose, glabrous; style 3, free to base, glabrous, 2.0−2.5 cm long. Capsule not seen.

Phenology: Flowering from January to February.

Distribution, habitat, and conservation status: Camellia zhaiana is only known from its type locality. It grows in the evergreen broad-leaved forests of the limestone mountains at the elevation of 30−100 m. This area has not yet been protected and there are plausible threats because it has great commercial value. Currently, only four individuals were found in the field, and no fruit was found in the last 4 years. It seems that it may be problematic in its natural regeneration. According to the Guidelines for using the IUCN Red List Categories and Criteria v.14 (IUCN 2019), C. zhaiana may be categorized as Critically Endangered (CR, B2ab (iv,v)).

Vernacular name: hong hua chang bing cha (红花长柄茶).

Etymology: The new species is named after local people Mr. Shi-Yao Zhai, who discovered the new species for the first time.

Additional specimens examined: CHINA. Guangxi: Long’an County, Qiaojian Town, on limestone in the evergreen broad-leaved forest, elev. 30−100 m, 16 March 2019, S. X. Yang, P. M. Ye & F. Y. Wu 6023 (KUN); 26 September 2019, S. X. Yang & P. M. Ye 6185 (KUN); 6 January 2020, S. X. Yang & P. M. Ye 6323 (KUN).

Comments: According to the classification of Chang (1981) and Ming (2000), Camellia zhaiana belongs to sect. Longipedicellata in having slender and elongate pedicels, 4-bracteoles, 5-sepals persistent, 3-loculed ovary and distinct style. It resembles C. longipedicellata in having pedicel slender, ovary 3-loculed and glabrous, style distinct, young branch sparsely puberulent, abaxial leaf surface scattered glandular spots, bracteoles persistent, filaments puberulent and outer filaments connate 2/3 from the base. However, C. longipedicellata has white and glabrous flowers, and smaller leaves. 

CHINA. Guangxi: Long’an County, Qiaojian Town

红花长柄茶 Camellia zhaiana S.X. Yang in Phytotaxa 460: 225 (2020).

灌木，高2.0−4.0米。幼枝呈圆柱形，紫褐色，稀疏青春期，很快无毛;顶芽稀疏发育。叶片薄而革质，椭圆形至长椭圆形，长7.0−10（−13.0）x 3.0−4.0厘米，顶端尖至尾状，基部楔形或宽楔形，边缘浅而圆，齿面浅而圆，背面为暗绿色且无毛，背面黄绿色，散布着深褐色腺斑，无毛，中脉向向下沉且向下侧隆起，中脉两侧各有6或7条次脉，向下侧略微凹陷，向下侧隆起， 第三脉脉非常模糊，轴向和可见的背脉;叶柄长2.0−4.0毫米，无毛。花顶端，单生，下垂，直径4.0（−6.0）厘米;花梗细长，黄绿色，长1.5厘米，顶端加厚，无毛;苞片4（−6），黄绿色，卵形至宽卵形，尺寸为1.0 x 1.0毫米至2.0 x 3.0毫米，无毛，边缘纤毛，持久性;萼片5（−8），黄绿色，尺寸3.0 x 5.0毫米至7.0 x 10.0毫米，宽卵形至羽状，无毛，边缘纤毛;花瓣14⁰16，每轮4⁻5，两侧略带扭曲，有茸毛，最外圈1.0 x 1.0厘米，圆形，半圆形，最内圈2.0 x 2.0厘米，近圆形至短椭圆形，基部连结长5.0−7.0毫米。雄蕊多，长约2.0厘米，外层花丝基部约2/3连成管状，有毛，内花丝明显，毛发距基部2/3;子房为三室，球形，无毛;花柱3，离基，无毛，长2.0−2.5厘米。开花期为一月至二月。

分布、栖息地及保护状况：红花长柄茶仅根据其模式产地被发现。它生长在海拔30−100米的石灰岩山脉常绿阔叶林中。该地区尚未受到保护，存在合理的威胁，因为它具有极高的商业价值。目前，田野中仅发现了四只个体，过去四年内也未发现任何果实。看来它的自然再生可能存在问题。根据IUCN红色名录第14版使用指南（IUCN 2019），C. zhaiana可能被归类为极危物种（CR， B2ab （iv， v））。

中国广西隆安县桥建镇