Cyrtopodium

Cyrtopodium is distributed from southern Florida, the West Indies, and Mexico to southern Brazil and Argentina. Brazil, with 39 species, is the country with the highest number of species, followed by Venezuela and Bolivia (9 species each), Paraguay (6), and Argentina, Colombia, Guyana, and Suriname (4 each). In Brazil, the center of diversity of the genus is the cerrado vegetation, where 29 species are found. The cerrado is a species-rich savanna vegetation covering 2 million km2 of Central Brazil (Ratter et al., 1997). One particularly species-rich area located at the core region of the cerrado vegetation (the Federal District), occupying an area of 5783 km,2 has 18 species (Batista and Bianchetti, 2003). Of the 39 species from Brazil, 25 are restricted to the country; 13 of the 29 occurring in the cerrado are restricted to this particular habitat. Some species are known from just a few or single areas, but narrow endemics are few. Venezuela has two species restricted to the country and El Salvador has one form. One species, Cyrtopodium cardiochilum, is of unknown origin and distribution, but it is probably conspecific with C. glutiniferum, which is restricted to Brazil.

Most of the species in the genus are terrestrial (33 species), some are epiphytic (7), and others strictly lithophytic (5), while a few can grow as terrestrials as well as lithophytes (3). The lithophytic and epiphytic species have invariably large, fusiform pseudobulbs bearing articulate leaves (that is, leaves with an articulation or abscission layer between the blade and the sheath of the leaf). The terrestrial species usually have smaller pseudobulbs that can be either above- or completely underground, bearing either articulate or non-articulate leaves. The terrestrial species are predominantly from open grasslands and occupy a broad range of habitats, from dry rocky slopes to wet meadows. Most of the species of the genus begin a new cycle of growth and flower at the end of the dry season and the beginning of the rainy season, usually February to April in the northern hemisphere or September and October in central and southeastern Brazil. A new vegetative shoot grows from the pseudobulb formed in the previous season. The reproductive shoot emerges from the base of the new vegetative shoot and, in most species of the genus, it develops rapidly so that when the plants are in full bloom the leaves are only partially developed; they become fully developed a few months after flowering. As the dry season approaches, the leaves wither and are eventually lost, and the plants become dormant. This seasonal habit, combined with the buried pseudobulbs of many species, renders locating the terrestrial species in the field during the dormant period a difficult task. Plants are most easily found when in flower, in places recently burned. Though apparently not strictly necessary, bush fires during the dry season dramatically favor flowering of the terrestrial species from open grasslands (Schomburgk, 1839; Menezes, 1994;). In many species, the inflorescence emerges almost immediately after a fire and the plants are in full bloom a few weeks later. Flowering of the species in unburned places is rare or infrequent, and for some species, we have never seen plants flowering at unburned sites. Cultivated plants can flower without fire, although at a lower frequency and only when exposed to hydric stress and full sun. The buried pseudobulbs of many of the terrestrial species from open grasslands are apparently adaptive: their placement below ground provides protection against the possibly high temperatures found in grassland fires.

Cyrtopodium R. Br. has a Neotropical distribution ranging from southern Florida to northern Argentina. Despite the showy flowers of many species, the genus has never received much attention from orchid enthusiasts and cultivators. Recently, with an ever increasing colonization of the cerrado of central Brazil and interest in orchids, many species have become available and interest in the cultivation of Cyrtopodium has grown. About 50 species are known in the genus with the greatest concentration found in Brazil. There are few specific works about the genus. The Brazilian species were revised by Cogniaux (1898–1902) in Flora Brasiliensis and Hoehne (1942) in Flora Brasilica. Warming (1884) and Menezes (2000) provided color illustrations and observations about the habitat and ecological preferences of many of the species. Sánchez (1986) reviewed the species found inArgentina. The species found along the Andes, however, have never been revised.

A total of 116 names have been proposed in the genus, 50 of which are currently accepted. Forty names are synonyms in the genus, 21 are referable to other genera, including Eulophia R. Br. (14), Koellensteinia Rchb.f. (3), Otostylis Schltr. (10), Eriopsis Lindl. (1), Tetramicra Lindl. (1), and Oncidium Sw. (1). Presently there are 47 species and three subspecific taxa (one subspecies, one variety, and one form), in the genus. The identity of five accepted species in the list is unclear and it is likely, with the exception of Cyrtopodium intermedium Brade, that they are conspecific with other, better known species. Five names are placed in the category of nomina nuda. Eight lectotypifications are proposed for the species described by Schlechter, Velloso, and Barbosa Rodrigues, whose types were lost. One new synonym is proposed, Cyrtopodium flavum Link & Otto ex Rchb., and is recognized as the accepted name for the widespread species formerly known as C. paranaensis Schltr. and C. polyphyllum (Vell.) F. Barros. Nineteen new and accepted species were described in the genus in the last 15 years, 11 of them from central Brazil, five from southern, southeastern, and northern Brazil, and three from northern South America (Venezuela, Ecuador, and Colombia). The systematic botanical exploration of the cerrado started only in the 1960’s and among the small terrestrial orchids, many species have been poorly collected and overlooked. Only because of recent field and taxonomic work in the region were these species discovered and described. It is likely that other new species are still to be discovered.