Lectotypification and New Synonymy in Quercus subg. Cyclobalanopsis (Fagaceae) Min Deng School of Ecological Technology and Engineering, Shanghai Institute of Technology, Shanghai 200235, People’s Republic of China, and Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, Yunnan, People’s Republic of China Zhe-Kun Zhou Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, Yunnan, People’s Republic of China. Author for correspondence: zhouzk@mail.kib.ac.cn Allen Coombes Herbarium and Botanic Garden, Benemerita Universidad Autonoma de Puebla, Puebla, Mexico. allen.coombes@hotmail.com ABSTRACT . The name Quercus cambodiensis Hickel & A. Camus (Fagaceae) is lectotypified herein. Based on morphological comparison and wild population observation, seven names within Quercus subg. Cyclobalanopsis (Oerst.) C. K. Schneid. (Fagaceae) are synonymized: Q. patelliformis Chun to Q. asymetrica Hickel & A. Camus; Cyclobalanopsis yingjiangensis Y. C. Hsu & Q. Z. Dong to Q. brevicalyx A. Camus; Q. cambodiensis Hickel & A. Camus, Q. camusiae Hickel & A. Camus, and C. pachyloma (Seemen) Schottky var. mubianensis Y. C. Hsu & H. W. Jen to Q. langbianensis Hickel & A. Camus; and Q. subhinoidea Chun & W. C. Ko and Q. chingsiensis Y. T. Chang to Q. thorelii Hickel & A. Camus. Key words: Fagaceae, Quercus, subgenus Cyclo- balanopsis. Subgenus Cyclobalanopsis (Oerst.) C. K. Schneid. in Quercus L. (Fagaceae) consists of about 150 species (Huang et al., 1999). Their distribution is restricted to East and Southeast Asia, with 69 species (43 endemic) in China. Most are important components of Southeast Asia’s broad-leaved evergreen forests (Huang et al., 1999). The rank status of Cyclobala- nopsis is an arguable issue in the taxonomy of Fagaceae. Most taxonomists treat the name as a subgenus of Quercus, based on the homologous origin of imbricate scales and concentric lamellae on the fruit cupules (Camus, 1938; Barnett, 1944; Soepadmo, 1968; Menitsky, 1984; Govaerts & Frodin, 1998). Cyclobalanopsis has been recognized at generic rank by other taxonomists (Schottky, 1912; Brett, 1964; Huang et al., 1998, 1999). Both the Flora Reipublicae Popularis Sinicae (vol. 22) and the Flora of China (vol. 4) recognized Cyclobalanopsis at the generic level. Molecular phylogenetic studies support two main clades in the genus Quercus: one broader clade composed of the largely New World section Lobatae Loudon, Quercus s. str., and section Protobalanus (Trel.) A. Camus, and a second monophyletic clade of the two strictly Old World groups, subgenus Cycloba- lanopsis and section Cerris Loudon, which lies sister to the New World clade (Manos et al., 1999, 2001; Oh & Manos, 2008). Herein, we adopt the subgeneric placement of Cyclobalanopsis and interpret Quercus at the generic level. 1. Quercus asymetrica Hickel & A. Camus, Bull. Mus. Natl. Hist. Nat. 29: 601. 1923. TYPE: Vietnam. Tonkin: Khe-va, Hai-ninh, 27 Sep. 1919, Casabianca s.n. (holotype, P; isotype, P). Quercus patelliformis Chun, J. Arnold Arbor. 28: 241. 1947, syn. nov. Cyclobalanopsis patelliformis (Chun) Y. C. Hsu & H. W. Jen, J. Beijing Forest. Univ. 15(4): 45. 1993. TYPE: China. Guangxi: Nan-Lin, Kuei-Kai Shan, 16 Oct. 1933, C. Wang 34658 (holotype, SYS not seen; isotype, A). Distribution and habitat. Quercus asymetrica oc- curs in evergreen forests of Guangxi and Hainan provinces in China and also extends into Tonkin (Bac Ky), Vietnam. Discussion. In the original description (Chun, 1947), Quercus patelliformis was characterized by highly connate, columnar styles and a somewhat NOVON 20: 400–405. PUBLISHED ON 29 NOVEMBER 2010. doi: 10.3417/2004208