Baptistonia and the Biome Atlantic Forest
Vitorino Paiva Castro
ON: Could you tell us about the subject of the poster you presented in Dijon?
VPC: It concerns the genus Baptistonia and the Biome Atlantic Forest. Most precisely the evolution of the biome "Atlantic Forest", during the first glacial area, it means within the 100.000 last years, the geological events, the climatic variations and the facts that give evidence of this. The genre Baptistonia is one of those genera, between other, which characterizes this evolution. The morphological aspects and the DNA sequences show the series of differences between this genus and the species of Oncidium. This presentation included the present status of the species and synonyms, the attempt of a classification of the species en subgenera and sections, the geographical distribution, the climate and the cultivation.
ON: So you consider Baptistonia as a good example for endemic genus for the Biome "Atlantic Forest". Formerly, the genus had just one species (Baptistonia echinata Barb. Rodr.), but you are talking about a classification of the species which is something new.
VPC: Guy Chiron and I have done a systematic study which resulted in the transference of the Oncidium species, inside the Walueva section and one species from the Crispa section (Oncidium sarcodes) to Baptistonia.
ON: Which are the species inside this genus, presently?
VPC: This genus is still being study so there is no a definitive list. According to the work we have published, they are: Baptistonia albini, ×amicta, brieniana; ×cassolana; cornigera; cruciata; echinata; fimbriata; gutfreundiana; kautskyi; leinigii; lietzei; nítida; pabstii; pubes; pulchella; remotiflora; riograndensis; sarcodes; silvana; truncata; velteniana; verrucosissima; widgrenii. However some names can be placed as synonym in a next work.
ON : Which is the geographical distribution of this genus?
VPC : This genus is endemic to the Biome “Atlantic Forest” and to occurs in the Brazil (since the south of the state of Bahia until the state of Rio Grande do Sul and also in the gallery forests in the north of Argentina and Paraguay.
ON: Besides Baptistonia, which are the other endemic species to the Atlantic Forest?
VPC: Pseudolaelia, Sophronitis, Sophronitella, Isabelia, Constantia, Pigmaeorchis, Leptotes, Loefgrenianthus, Hoffmannseggella, Dungsia, Hadrolaelia, Microlaelia, Cattleya (bifoliate), Grobya, Promenaea, Cirrhaea,
Pabstia, Neogardneria, Hoehneella, Bifrenaria (except for 2 species), Gomesa, Binotia, Rodrigueziella, Zygostates, Centroglossa, Sanderella, Ornithophora, Rodrigueziopsis, Chytroglossa, Platyrhiza, Thysanoglossa, Saundersia.
ON: In this work, you used a tool which is rare used to get knowledge of orchids. What is this tool and which are, in general, the data required to get a good knowledge?
VPC: A good knowledge about the vegetal kingdom and specially the orchids requires many data. Someone of them wide used since long time ago, such as the morphological characters, the climate, the altitude, and some of them just recently employed such the DNA sequence since the 80s and mainly in the 90s. However there is another information, rare used but which can be revealed as useful for the knowledge of the orchids, the study of the plants evolution attached to the geological chronology and related to the continents formation and geological and climatic events which the fauna and flora should face along the time.
ON: With this tool or information, as you said, is possible to determinate the date of orchids origin?
VPC: There is no exact date of orchids origin of the because since they don't have ligneous structures, they easily decompose and don't let fossil residues. However one can notice the existence of common species to some continents such as Eulophia alta, in common with African and American continents or even determined genus which are pan continental such as Bulbophyllum and Habenaria.
ON: Which is your explanation for the distribution of Eulophia alta?
VPC: The hypothesis of seeds diffusion related to the trade between America and Africa since the XVI century seems not to be very convinced to us. Then, if we admit its existence in the old continent Gondwana, formed by the tectonic plaques of the present South American, Africa, Madagascar, India, Australia and Antarctic, one can suppose that the orchids, at least, the terrestrial, already existed in the time of the rupture and separation of the South American from Africa, at about 150-130 millions years ago.
ON: Thank you very much.