As Orchidaceae são muito apreciadas por suas flores exóticas e exuberantes. É a maior família de plantas apresentando mais de 24000 espécies, o que denota uma alta diversidade de formas e adaptações a diferentes ambientes, como também para atração, engano e manipulação de visitantes na realização da polinização cruzada. Cattleya eldorado ocorre em áreas de campinas, que são formações vegetais típicas da região amazônica, que se encontram sob forte ação antrópica. Este trabalho tem como um de seus principais objetivos conhecer parte dos processos biológicos de C. eldorado fornecendo subsídios para conservá-la e manejá-la em seu habitat natural. Este estudo foi desenvolvido na Reserva Biológica de Campina, de 2000 a 2006, durante a sua floração. C. eldorado é uma espécie epifítica que apresenta a síndrome de melitofilia, estando adaptada ao seu polinizador, a abelha Eulaema mocsaryi, que reconhece suas flores pelo odor e pelo estímulo visual através de sua coloração e reflexão de luz ultravioleta. C. eldorado é uma espécie autocompatível, embora necessite de um agente polinizador para a transferência do polinário até sua deposição na cavidade estigmática da flor.

The orchid plants are highly prized for their lush exotic flowers. It is the largest plant family with more than 24000 species, which indicates a high diversity of forms and adaptations to different environments, including the capacity to attract, deceive and manipulate visitors involved in cross-pollination. Cattleya eldorado occurs in areas of white sand campinas, a typical vegetation type of the Amazon region, which is under strong anthropogenic pressure. This work's main objectives to know the biological processes of C. eldorado providing subsidies to maintain and manage it in its natural habitat. This study was conducted from 2000 to 2006 in the Campina Biological Reserve, during its flowering period. C. eldorado is an epiphytic orchid species that has the melittophyly syndrome and is adapted to its pollinator, the bee Eulaema mocsaryi recognizing their flowers by smell and by visual stimuli, through their color and reflection of ultraviolet light. C. eldorado is self-compatible, even if it requires a pollinating agent for the transfer of the pollinarium until its deposition in the stigmatic cavity of the flower.

Foi estudada a biologia floral, o sistema reprodutivo e a fenologia de Pseudolaelia corcovadensis (Orchidaceae), na Estação de Pesquisa e Desenvolvimento Ambiental de Peti, São Gonçalo do Rio Abaixo, Minas Gerais. A espécie floresce de abril a setembro, com pico de floração em junho e julho. As flores são rosa-escuro, fortemente zigomorfas, possuem osmóforos e guias de néctar que absorvem luz ultra-violeta. Porém, as flores de P. corcovadensis não possuem néctar, sendo polinizadas por Bombus (Fervidobombus) atratus Franklin, 1913 (Hymenoptera: Apidae) através de mecanismo de engodo. Aparentemente as flores não formam um par mimético com outra espécie na comunidade, mas mimetizam um modelo generalizado de flor melitófila que oferece recompensa. Como conseqüência, as visitas são muito raras e a frutificação é relativamente baixa (18%). Pseudolaelia corcovadensis é autocompatível e apresenta depressão endogâmica nos estágios iniciais de desenvolvimento. O posicionamento filogenético do gênero Pseudolaelia, aliado a estudos de biologia floral em gêneros próximos, permite indicar que melitofilia e autocompatibilidade sejam características basais na subtribo Laeliinae, com posterior radiação adaptativa para polinização por beija-flores, Lepidoptera, Diptera e outros Hymenoptera.

The floral biology, mating systems and phenology of Pseudolaelia corcovadensis (Orchidaceae), in the "Estação de Pesquisa e Desenvolvimento Ambiental de Peti", São Gonçalo do Rio Abaixo, Minas Gerais state was studied. This species flowers from April to September, with a higher availability of flowers in June and July. The flowers are dark-pink, strongly zygomorphic, and have osmophores and nectar-guides absorbing ultraviolet light. However, the flowers of P. corcovadensis do not present nectar and are pollinated by Bombus (Fervidobombus) atratus Franklin, 1913 (Hymenoptera: Apidae) by deceit. Apparently, the flowers do not form a model-mimic pair with other species in the community, but mimic a generalized melittophilous food-flower. As a consequence, visits are very rare and fruit set is low (18%). Pseudolaelia corcovadensis is self-compatible and presents inbreeding depression in the early stages of development. The phylogenetic position of the genus Pseudolaelia and studies on floral biology in related genera suggest that melittophyly and self-compatibility are basal characters in the subtribe Laeliinae, with subsequent adaptive radiation to pollination by hummingbirds, Lepidoptera, Diptera and other Hymenoptera.

Resumo Com o presente taxon, proposto sob o nome de X Brassocattleya rubyi, eleva-se para quatro o número de taxa do gênero híbrido ocorrentes no Brasil. Pela primeira vez descreve-se, nesta região, um taxon pertencente a este gênero, aumentando também o número de espécies da Reserva Biológica de Campina INPA/SUFRAMA (estrada Manaus-Caracaraí, km 45).

Summary In this paper, the author describes a new natural hybrid of Brassocattleya (Orchidaceae) from the Amazonian region, thus extending the number of taxa of this hybrid genus to four in Brazil. By analysis of floral biology and probability of hybridization, we could verify the high degree of isolation between C. eldorado and B. martiana, an important aspect in the evolution of this family.

Resumo Com a presente espécie, proposta sob o nome de Masdevallia osmariniana, eleva-se para nove o número de taxa do gênero ocorrentes na Amazônia. Pela primeira vez descreve-se, nesta região, uma espécie pertencente ã seção Rhombipetala.

Summary In this paper the autor discribes a new species of Masdevallia (Orchidaceae) from amazoniam region. Now the number of species of that genus extendes to nine in this region. The new species M. osmariniana, differes mainly from the nearest species, M. o'brieniana in the linear-lanceolate leaves, petals 2-venoses, unguiculo costulated, lip apex denticulate, column with auricles erose in the base and corniculate at the apex and. finally, by clinandrium at the apex bipartite.

RESUMO Neste trabalho, estudou-se a taxonomia, distribuição geográfica, fenologia e biologia floral das Orchidaeeae da Reserva Biológica de Campina, estrada Manaus-Caracaraí, km 62. Apresentou-se também, uma tabela comparativa de todas as orquídeas já coletadas ou citadas das campinas da Amazônia Central. Coletou-se Bulbophyllum correae Pabst pela primeira vez fora do local da descrição original e indicou-se Ornithidium parviflorum (Poepp. & Endl.) Rchb, f. como nova para o Estado do Amazonas. Os espectros fenológicos aos espécies da campina estudada foram bastante variáveis, estando dispersos pelos 12 meses do ano. A maioria das síndromes de polinização das plantas da Reserva Biológica mostrou-se adaptada aos Hymenoptera; a seguir vieram os Lepidoptera, os Diptera e os Trochillidae. Rodriguezia secunda H.B.K. foi anteriormente reportada como sendo polinizado por Trochillidae. Neste estudo, observou-se Heliconius hermanthena (Hewitson) (Lepidoptera) como o real polinizador na área.

SUMMARY This study is concerned with the taxonomy, geographical distribution, phenology and floral biology of species of Orchidaceae found at the Campina Biological Reserve (Manaus-Caracaraí Road, Km. 62). A list of the orchids collected from or cited as occurring in campinas of Central Amazonia has also been included for comparison. A total of 24 genera and 48 species of orchids were found in the campinas studied. Encyclia fragrans (Sw.) Lemée was found to be the most common species. The number of endemic species appeared to be small, 9.67%. Only Bulbophyllum correae Pabst, Encyclia tarumana Schltr., and Maxillaria pauciflora Barb. Rodr. appeared as species characteristic of this community. 31 species belonging to 17 genera were found at the Campina Reserve, and most species had a broad range of distribution. Bulbophyllum correae Pabst was collected here which extended its previously described range, and Ornithidium parviflorum (Poepp. & Endl.) Rchb. f. was collected for the first time in the state of Amazonas. The phenology of the species was variable throughout the twelve months of the year, and the phenology of species belonging to the same genus was also variable. The months of little flowering activity with the rainy season when insolation, radiation and temperatures were low. During the season of less rain, prior to the budding period, temperatures dropped to an absolute minimum of 19.0°C. This probably induced the species which flower during the rainy season to be activated at this time, when normally they would not flower. The months of greatest flowering coincided coincided with the relatively dry months, when radiation, temperatures and insolation were high. Only Epidendrum huebneri Schltr. of all the flowering species, blossomed all year round. In relation to the vegetative development there did not seem to be a marked difference between those species which flowered during the dry and wet seasons respectively. The genus Catasetum was the only one to lose its leaves during the dry season. The majority of pollinization syndromes of the plants found at the Campina Reserve showed adaptation to Hymenoptera, Lepidoptera, Diptera and Trochillidae (in that order). The plants produced odor mostly during the morning. Few species produced odors at night or during the afternoon. Three species did not produce odors. Rodriguezia secunda H.B.K. was previously reported as being pollinized by Trochollidae. However, it was observed that Heliconius hermanthena (Hewitson) (Lepidoptera) seemed to be the real pollinator in the area. Analysing the floral syndrome of this species, it was concluded that the species syndrome encompasses the two types of pollinators. This is of great importance from the evolutionary point of view of this species, as the campina population is isolated from other populations, and this could encourage future occurrence of speciation. The majority of the species need a pollinizing agent for effective fertilization according to the data on pollination and fertilization. Only Epidendrum strobiliferum Rchb. f. was autogamous. Once the number of seeds per capsule in this family is taken into consideration, the average computed for pollinization and fruiting is significant, 0.49 and 0.52 respectively. The fact that the average for fruiting is higher than the average for pollinization at first seems contradictory. However, this questionable result is explained by the autogamy of Epidendrum strobiliferum, which influences the numerical results. Insofar as the relationship between the pollination mechanisms and pollinizing agents is concerned, it was noted that the pollinia adheres specifically and precisely. This is of great importance in maintaining the specificity of the pollinizing mechanism. It was noted that animals other than specific pollinizing agents also visited the flowers, but they either did not carry pollinia, or their visit did not result in pollinization.

Resumo O autor com este trabalho começa uma série sobre as orquídeas do Amazonas e sua biologia floral. Nesta primeira publicação, foi analisada a biologia floral de Stanhopea candida Barb. Rodr. Esta espécie foi incluída no grupo grandiflora, pois possui mecanismo da polinização do tipo "queda". As estratégias de atração da espécie também são bem elaboradas. Quanto à sua polinização, na região de Manaus, Eulaema mocsaryi é o polinizador efetivo, enquanto que Euglossa ignita comporta-se como "ladrão de odor".

Summary This is the first of a series of articles on orchids of the state of Amazonas, and their floral biology. In the present paper, the floral biology of Stanhopea candida Barb. Rodr. was studied. The species was included in the grandiflora group due to its pollination by a "fall through" mechanism. The attractant strategies of the species are elaborate. Pollination, in the vicinity of Manaus, is carried out by Euiaema mocsaryi, as effective pollinator, while Euglossa ignita acts as an "odor thief".

Resumo Para complementar o trabalho de Anderson et al. (trabalho anterior) sobre a vegetação da campina, foram investigados três aspectos ecológicos adicionais, os quais não constavam na programação dos trabalhos de tese dos alunos do mestrado do INPA. No primeiro estudo, analisadas 50 ilhas pequenas que ocorrem na campina aberta (1). com um total de 25 espécies de plantas lenhosas e algumas plantas herbáceas, relacionando-se o tamanho das ilhas, a ocorrência das espécies e as associações entre as mesmas. No segundo, verificada a ocorrência de duas espécies de Loranthaceae, hemiparasitas, que ocorrem na campina aberta e sombreada (1), com tendência a terem hospedeiros específicos. Phthirusa rufa (Mart.) Eichl. (Loranthaceae) tem como hospedeiro Ouratea spruceana Engl. (Ochnaceae) e Phthirusa micrantha Eichl. (Loranthaceae) tende, entre outras espécies, a parasitar Hirtella racemosa Lam. var. racemosa (Chrysobalanaceae). Aspectos anatômicos e ecofisiológicos foram relacionados. No último trabalho ecológico foi analisada a ocorrência de algumas epífitas em cinco espécies de árvores na campina (aberta e sombreada) e na campinarana.

Summary We investigated three ecological aspects of the vegetation of an Amazonian campina The subjects studied were chosen to complement the study of Anderson et alii (1975) and the thesis studies of students of INPA. The first part is an analysis of the small islands of vegetation which occur in the open campina. We found a total of 25 species of woody plants and we also studied some herbaceous species. Data is presented on the occurrence of species and the associations between them and their correlation with island size. The second part is a study of two species of Loranthaceae (Phthirusa rufa (Mart.) Eichl. and P. micrantha Eichl). These hemi-parasites occur in the open and shady areas of the campina and show a tendency to have specific nosts, especially Hirtella racemosa Lam. var racemosa (Chrysobalanaceae) in the case of P. micrantha, and Ouratea spruceana Engl. (Ochnaceae) in the case of P. rufa. Some anatomical and ecophysiological aspects of this host-parasite relationship are also discussed. The final part is an analysis of the occurrence of some selected species of epiphytes in five species of trees which are common in the campina. The study was made in both sun and shade campina, and also in campinarana.

Resumo Estudo das Rhizophoraceas da Amazônia abrangendo 5 gêneros: Rhizophora, Cassipourea, Sterigmapetalum, Polygonanthus e Anisophyllea. Doze espécies dos referidos gêneros são estudadas e descritas. Novos taxa não foram encontrados, porém, diversos nomes foram colocados em sinonímia. Apresentada a descrição do pólen de algumas espécies.

Summary A taxonomic revision of the Amazonian species of Rhizophoraceae was made. There are 5 genera and 12 species represented in the area. No new taxa were found and several existing names were reduced to synonomy. Comments are given on the relationship of various species and the distribution of each species is given on maps. Some information about the polen grains is given too.