202 ORCHIDS MARCH 2005 WWW.AOS.ORG l LINDLEYANA THE BRITISH BOTANIST Robert Brown described the genus Brassia in 1813 to accommodate a group of species related to Oncidium that were characterized by long, almost caudate sepals and petals. The genus was dedicated to William Brass, botanical illustrator, who collected plants in West and South Africa under the employment of Sir Joseph Banks. The type species for the genus, Brassia maculata, was described in the second edition of Hortus Kewensis on the basis of a plant imported from Jamaica by J. Banks. In 1824, John Lindley transferred to Brown’s genus Epidendrum caudatum, which was published by Linnaeus in 1763 on the basis of a name proposed by Plumier for a plant from the West Indies. THE GENUS BRASSIA The common name for Brassia species — spider orchids — refers to the characteristic shape of the flowers, which resemble large spiders. Apparently, this similarity is also the base of the pollination syndrome for Brassia. As noted by Dodson (van der Pijl and Dodson, 1966), species of Brassia are pollinated by female spider-hunter wasps of the genera Pepsis and Campsomeris . The wasps sting and paralyze the spider to drag it to the nest, where they lay an egg in the anesthetized body, which then serves as living food for the developing larva. Due to the mimicry of the flowers, the wasp stings the lip and repeatedly tries to drag its prey; during this unsuccessful effort, the pollinarium adheres to the insect’s head. This observation was recently confirmed in southern Costa Rica, where large Pompilid wasps were observed trying to sting the flowers of Brassia cf. caudata. Norris H. Williams segregated Brassia section Glumaceae, which includes the species with enlarged floral bracts and mostly reduced pseudobulbs, into the genus Ada (Williams, 1972). Species of the genus Brassia in the strictest sense can be easily recognized by the rather large plants with conspicuous, one- to two-leaved pseudobulbs, lateral inflorescences with small floral bracts, spider-shaped flowers with spreading, elongate sepals and the lip free from the column and a pollinarium provided with a narrow stipe. FRANCO PUPULIN 2 AND DIEGO BOGARÍN ABSTRACT: The genus Brassia is discussed in general; its pollination syndrome, molecular phylogeny and taxonomic position. The four previously recognized Costa Rican species are discussed and a new species, Brassia suavissima Pupulin & Bogarín, is described. Jardín Botánico Lankester, Universidad de Costa Rica, PO Box 1031-7050 Cartago, Costa Rica, AC 1 We thank Marta Herra, Adolfo Quesada-Chanto, Rafael Ángel Valverde and Esteban Víquez Jiménez, of the Fundación Orquídeas de Costa Rica, for calling our attention to the distinctiveness of Brassia plants in their collections and for making material available for study. We also thank Gustavo A. Romero, Harvard University Herbaria, for providing documentation on Brassia species, and Norris H. Williams, Florida Natural History Museum, University of Florida, for his suggestions and observations that greatly improved this manuscript. 2 Author for correspondence, e-mail: fpupulin@cariari.ucr.ac.cr. THE GENUS BRASSIA IN COSTA RICA: A SURVEY OF FOUR SPECIES AND A NEW SPECIES 1 Fig. 1. In some clones of Brassia arcuigera, individual flowers may be longer than 50 cm (20 inches). Photographs by Franco Pupulin. We tried to match the style and layout of the old Lindleyana and came pretty close, I think.