Brasiliorchis: A New Genus for the Maxillaria picta Alliance (Orchidaceae, Maxillariinae) Rodrigo B. Singer Departamento de Bota ˆnica, Instituto de Biocie ˆncias, Universidade Federal do Rio Grande do Sul, Av. Bento Gonc ¸alves 9500, Bloco IV, Predio 43432, Sala 207, Bairro Agronomia, CEP 91501-970, Porto Alegre, Rio Grande do Sul, Brazil. rbsinger1@yahoo.com Samantha Koehler Departamento de Bota ˆnica, Instituto de Biologia, Universidade Estadual de Campinas, Caixa Postal 6109, 13083-970, Campinas, Sa ˜o Paulo, Brazil. samantha.koehler@googlemail.com Germa ´ n Carnevali Herbarium CICY, Centro de Investigacio ´n Cientı ´fica de Yucata ´n A. C., Calle 43, No. 130, Col. Chuburna ´ de Hidalgo, 97200 Me ´rida, Yucata ´n, Me ´xico. carneval@cicy.mx ABSTRACT . Brasiliorchis R. Singer, S. Koehler & Carnevali is here proposed to include the orchid species formerly recognized in the Maxillaria picta alliance, an orchid group mostly endemic to the Atlantic Rain Forest Biome, in south and southeastern Brazil. The new genus is supported by both morpho- logical features and ongoing molecular studies. The new genus is easily diagnosed by its sulcate to ridged, bifoliate pseudobulbs and its long-lasting, campanu- late, rewardless flowers. The pollinaria of these flowers are normally devoid of stipes. Formal diagnosis of the genus and 13 taxonomic combinations are presented: Brasiliorchis barbozae (Loefgren) R. Singer, S. Koehler & Carnevali, B. chrysantha (Barbosa Rodrigues) R. Singer, S. Koehler & Carnevali, B. consanguinea (Klotzsch) R. Singer, S. Koehler & Carnevali, B. gracilis (Loddiges) R. Singer, S. Koehler & Carnevali, B. heismanniana (Barbosa Rodrigues) R. Singer, S. Koehler & Carnevali, B. kautskyi (Pabst) R. Singer, S. Koehler & Carnevali, B. marginata (Lindley) R. Singer, S. Koehler & Carnevali, B. phoenicanthera (Barbosa Rodrigues) R. Singer, S. Koehler & Carnevali, B. picta (Hooker) R. Singer, S. Koehler & Carnevali, B. polyantha (Barbosa Rodrigues) R. Singer, S. Koehler & Carnevali, B. porphyrostele (Reichenbach f.) R. Singer, S. Koehler & Carnevali, B. schunkeana (Campacci & Kautsky) R. Singer, S. Koehler & Carnevali, and B. ubatubana (Hoehne) R. Singer, S. Koehler & Carnevali. Lectotypes are designated for B. barbozae, B. chrysantha, B. heismanniana, B. phoeni- canthera, B. picta, and B. polyantha. A neotype is proposed for B. consanguinea. In addition, a key to distinguish Brasiliorchis from other sympatric bifoliate orchids within Brazilian Maxillariinae is presented. RESUMO . O ge ˆnero Brasiliorchis R. Singer, S. Koehler & Carnevali, e ´ proposto para conter aquelas espe ´cies de orquı ´deas antes incluidas na Alianc ¸a Maxillaria picta; um agrupamento primariamente ende ˆmico do bioma Mata Atla ˆntica, no Sul e Sudeste do Brasil. Este novo ge ˆnero e ´ sustentado tanto por caracteres morfolo ´gicos quanto por estudos de biologia molecular em andamento. O novo ge ˆnero e ´ facilmente diagnosticado pelos seus pseudobulbos bifoliados, sulcados a canaliculados e pelas suas flores campanuladas, duradouras e sem recompensas florais. Os polina ´rios destas espe ´cies normalmente carecem de estipes. Apresenta-se a diagnose formal do novo ge ˆnero, bem como treze novas combinac ¸oes taxono ˆmicas: Brasiliorchis barbozae (Loefgren) R. Singer, S. Koehler & Carnevali, B. chrysantha (Barbosa Rodrigues) R. Singer, S. Koehler & Carnevali, B. consanguinea (Klotzsch) R. Singer, S. Koehler & Carnevali, B. gracilis (Loddiges) R. Singer, S. Koehler & Carnevali, B. heismanniana (Barbosa Rodrigues) R. Singer, S. Koehler & Carnevali, B. kautskyi (Pabst) R. Singer, S. Koehler & Carnevali, B. marginata (Lindley) R. Singer, S. Koehler & Carne- vali, B. phoenicanthera (Barbosa Rodrigues) R. Singer, S. Koehler & Carnevali, B. picta (Hooker) R. Singer, S. Koehler & Carnevali, B. polyantha (Barbosa Rodrigues) R. Singer, S. Koehler & Carnevali, B. porphyrostele (Reichenbach f.) R. Singer, S. Koehler & Carnevali, B. schunkeana (Campacci & Kautsky) R. Singer, S. Koehler & Carnevali e B. ubatubana (Hoehne) R. Singer, S. Koehler & Carnevali. Sa ˜o propostos lecto ´tipos para B. barbozae, B. chrysantha, B. heismanniana, B. phoenicanthera, B. picta e B. polyantha. Propo ˜e-se um neo ´tipo para B. consangui- NOVON 17: 91–99. PUBLISHED ON 23 APRIL 2007.