老挝茶 Camellia laotica (Gagnep.) T.L.MingCamellia laotica

Camellia laotica (Gagnep.) T.L.Ming. Acta Bot. Yunnan. 21: 153 (1999). Lectotype (first-step designated by Sealy [1958: 222]; second-step designated by Zhao et al. [2017a: 176]): LAOS. Savannakhet: entre Lang a xinhxa ne et L. xoan, 10 April 1927, E. Poilane 13693 (P 04511456! Image: https://science.mnhn.fr/institution/mnhn/collection/p/item/p04511456).

• Zhao, D.W. (2024). Taxonomic revision of Camellia (Theaceae) in Thailand. PhytoKeys 239: 29-57. 

Description

Shrubs up to 5 m tall. New branchlets puberulous; terminal buds pubescent. Petioles 2–5 mm long, puberulous; leaf blades elliptic to oblong, 4–9 × 1–4.3 cm, thinly coriaceous, abaxially sparsely appressed pubescent, especially along midrib, adaxially glabrous, midrib and secondary veins abaxially elevated and adaxially channelled, secondary veins 6–8 on each side of midrib, base attenuate, margin sparsely serrulate, apex attenuate to shortly caudate. Flowers solitary or up to 3 in a cluster. Pedicels 7–14 mm long, glabrous or puberulous at base. Bracteoles 2, opposite or alternate, caducous. Sepals 3–4, persistent, sub-orbicular or broadly ovate, 3–8 × 6–9 mm, abaxially glabrous, adaxially sericeous, margin ciliolate. Petals 5, white, broadly ovate to obovate, 8–12 × 5–7 mm, glabrous on both surfaces, margin ciliolate. Stamens numerous, 5–7 mm long; filaments glabrous. Ovary ovoid, glabrous. Style 1, 5–7 mm long, glabrous, apically 3–5-lobed for 1–2 mm. Capsule globose, 12–20 mm in diam.; pericarp 2–3 mm thick. Seeds glabrous when immature.

Phenology

Flowering October, fruiting April–August.

Distribution and habitat

Camellia laotica is distributed in the evergreen or mixed deciduous forests at elevations of 400–750 m in Laos and Thailand.

Additional specimens examined

Ubon Ratchathani: Khong Chiam, Ban Na Klang Pho, Dong Na Tham forest, ca. 400 m, 24 October 1998, Wongprasert s.n. (BKF SN121590, BKF SN121591).

Notes

Gagnepain (1942) described the species based on three gatherings, including Poilane 13268, 13693 and 13743. Sealy (1958) suggested that Poilane 13268 and 13693 represented C. laotica whereas Poilane 13743 was a distinct species, which was subsequently given a name, C. sealyana T.L. Ming by Ming (1999). Sealy (1958) and Ming (2000) supplied a short description of C. laotica, without the characters of flowers, based on two gatherings (Poilane 13268 & 13693) in Laos. I add an account of flowers and provide a detailed description above.

Camellia laotica is a new record to Thailand. It is represented by a single collection, Wongprasert s.n. at BKF. The specimen was collected in Eastern Thailand, along Thai-Laos border. The leaves of C. laotica in Thailand seem to be narrower than those of the syntypes (Poilane 13268 & 13693) from Laos, and they do not bear cork-warts on the abaxial surface by which C. sealyana (cork-warts present) can be distinguished.

Camellia laotica has most recently been assessed for The IUCN Red List of Threatened Species in 2015. Camellia laotica is listed as Data Deficient.

Laos and Thailand

老挝茶 Camellia laotica (Gagnep.) T.L.Ming in Acta Bot. Yunnan. 21: 153 (1999). 

模式：Lectotype(第一步由Sealy [1958: 222] 指定；第二步由Zhao等人 [2017a: 176] 指定)： LAOS. Savannakhet: entre Lang a xinhxa ne et L. xoan, 10 April 1927, E. Poilane 13693 (P 04511456！）

灌木，高达 5 米。新小枝被微柔毛；顶芽被短柔毛。叶柄长2-5毫米，被微柔毛；叶片椭圆形到长圆形， 4-9 x 1-4.3 厘米，薄革质，背面疏生贴伏短柔毛，特别是沿中脉，正面无毛，中脉和次脉背面隆起，正面有沟，次脉在中脉两侧各6-8条，基部渐狭，边缘疏生细锯齿，先端渐狭到短尾状。花单生或最多 3 朵成簇。花梗长 7-14 毫米，无毛或基部被微柔毛。小苞片 2，对生或互生，早落。萼片 3-4 ，宿存，近圆形或宽卵形， 3-8 x 6-9 毫米，背面无毛，正面被绢毛，边缘具短缘毛。花瓣 5，白色，宽卵形到倒卵形， 8-12 x  5-7 毫米，两面无毛，边缘具短缘毛。雄蕊多数，长 5-7 毫米；花丝无毛。子房卵球形，无毛。花柱1，长5-7毫米，无毛，顶部3-5裂达1-2毫米。蒴果球状，直径12-20毫米；果皮厚2-3毫米。种子未成熟时无毛。

老挝茶最近一次于 2015年进行了IUCN濒危等级评估，被评为数据缺乏 Data Deficient（DD）。