by Luiz Menini Neto

The state of Minas Gerais occupies 588.384 km2, which corresponds at about 7% of the national territory, enclosing inside its area, part of the three big Brazilian biomes: caatinga (*), Atlantic Forest and cerrado (savannah), that, together, shelter a great variety of distinct phytophysiognomies, resulting in an admirable diversity (Costa et al., 1998).
In the state, we should point out the rupestrian fields (campos rupestres), a herbaceous-undershrub vegetation which occurs in mountainous areas above 900 meters, recognized by the great richness of species and endemism (Joly, 1970; Giulietti et al. 1987, 2000; Menezes & Giulietti, 2000).
The flora of the state has suffered and still suffers with the vast areas destroyed all along the centuries, due to the various economical cycles by which the country underwent. This becomes worrying as, still today, little is known about the diversity existent in this big state and much has been destroyed em high velocity, by deforestation for the plantation, pasturage and/or the mining.
Floristic surveys including terrestrial or epiphyte herbs, occurring in wood areas, in special those inside the family Orchidaceae, are rare for the state. In this way, the surveys are necessary aiming to know and to preserve what still resists to the devastation provoked by the man.
A compilation of the results of some works with Orchidaceae from the state of Minas Gerais will be present bellow (published in the magazines Rodriguésia 55(84): 137-156. 2004; Lundiana 5(1): 9-27. 2004; and Boletim CAOB 48(2): 35-40. 2002, respectively– the last one just present partial data). Those works are part of the floristic surveys of the vascular species in the three areas.


Work done in association of
Valquíria R. Almeida (Second university degree in course- National Museum/ UFRJ) and
Rafaela C. Forzza (Botanical Garden of Rio de Janeiro)


Foto / Photo: R. C. Forzza


The Biological Reserve of Grama Dam (RBRG) included an area of 263,8 hectares comprehending the physiognomies of semidecidous montane forests, alluvial forests and semideciduous broadleaved forests.
This is an important Atlantic Forest remaining, located in the municipal district of Descoberto, in the "Zona da Mata" (Forest zone) of Minas Gerais.
The area has six sources which flow into two brooks where the

water is impounded to the partial supply of the municipal districts of Descoberto and São João Nepomuceno. Due to the status of “biological reserve”, the visitation is not allowed to the population, helping in a certain way, the preservation. On the other hand, the action of the hunters and palmiteiros (**), as well the felling of the trees and the transformation of some areas in pasturage are a menace for both fauna and flora of the Reserve. Those agents, allied to the fact that there is only one guard responsible for the area, can put in danger the future of the biological diversity.


The family Orchidaceae is represented in RBRG for 27 species curiously distributed in 24 genera (Table 1), just three genera have two species: Epidendrum, Gomesa and Polystachya.
Comparettia coccinea, Huntleya meleagris, Psilochilus modestus, Vanilla cf. gardneri, Warrea warreana and Xylobium variegatum are perhaps the rarer species of Orchidaceae species within the Reserve, all of them known only by one population, the first one is quite reduced. On the other hand, Gomesa recurva has a broad distribution, with big populations spreading from the base until the crown of the trees.
Epidendrum secundum presents just a big population, in a rocky next to a brook. Regarding to the other species of Epidendrum occurring in the Reserve, E. densiflorum, just two individuals distant 20 meters from each other have been observed, hanging over a course of water, in half shade, one epiphytic another rupicolous.
Species such as Eltroplectris janeirensis, Oeceoclades maculata, Prescottia stachyodes, Sauroglossum nitidum, all of them terrestrial, have been observed in shade places in many points of the Reserve, although in the most of the time as isolated individuals or a few close individuals, never forming a big population.
Another taxon that should be point out is Wullschlaegelia aphylla which had just a collecting registered for Minas Gerais, in 1856 (Born et al. 1999), it could be a rare species, little collected as it is little conspicuous or even for being misidentified in the herbariums, due to the similarity to the Burmanniaceae's species. In the Reserve, this species, of saprophytic habit, has been observed in a big population in the ground of the wood, in shade place. We can also point out the first register of Polystachya micrantha for the state, just referred before to the states of São Paulo and Rio Grande do Sul, according to Pabst & Dungs (1975).
It is worth to stand out the occurrence of the species such as Cyrtopodium cardiochilum and Eltroplectris janeirensis, just registered for the state of Minas Gerais and Rio de Janeiro (Pabst & Dungs, 1975; Menezes, 2000); Eurystyles actinosophila with register for the states of Minas Gerais, Rio de Janeiro and São Paulo (Pabst & Dungs, 1975) and another such as Catasetum cernuum, Comparettia coccinea, Encyclia patens, Gomesa recurva and Pleurothallis hypnicola distributed through the states of south and southeast region of Brazil (Pabst & Dungs, 1975, 1977). The geographical distribution of those species has, possibly, a close relation with the Atlantic Forest remaining which appears in those states.


Foto / Photo: R. C. Forzza
Catasetum cernua (male inflor.)
Foto / Photo: R. C. Forzza
Catasetum cernua (fem. inflor.)
Foto / Photo: L. Menini Neto
Sauroglossum nitidum

Foto / Photo: R. C. Forzza
Huntleya meleagris
Foto / Photo: L. Menini Neto
Cyrtopodium cardiochilum
Foto / Photo: R. C. Forzza
Cyrtopodium cardiochilum (habitat)


The attention should be done to the number of terrestrial species (more than a third of the species) because in the rare floristic surveys of the family Orchidaceae is included many times that the terrestrial individuals represent a small percentage of the total.
The data presented here show the ecological importance of the Biological Reserve of Grama Dam and give help to the proposal of preservation of the Atlantic Forest remaining, biome considered as one of the 25 worldwide hotspots (areas with great concentration of endemic species - it means, species occurring just in a determined local – no matter if they are animal or vegetable, and with an accelerated lost of habitat) (Myers et al., 2000), at the risk of losing great part of the diversity of the flora and also of the fauna that Brazil still presents.
(*) Caatinga: Region of drought area of Brazil with stunted sparse typical vegetation.
(**) Palmiteiros: People who hunt and sell heart of palm trees.



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