Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

We present the first record of Maxillaria aureoglobula from Brazil, found at Mato Grosso State, in Southern Amazon. A description, illustration, photos and comments about the species are provided. 

Telipogon phuyupatamarcensis is a Peruvian endemic and poorly known species. Living specimens of various populations were examined. An updated description, illustrations, figures and taxonomic notes are provided. 

Tropical Latin America is a nexus of tectonic plates whose relative motions have led to rapid tectonic and volcanic mountain building in late Neogene time. Tropical mountain building, in turn, leads to highland “cloud forest” microclimates with increased rainfall, lower diurnal temperatures, and diverse microclimates. I have previously emphasized how the geologically recent growth of mountains has been localized in Central America and that this is likely a factor in the high diversity and endemism in those highlands. This paper will show that Andean uplift accelerated at ~15 Ma ago and ~ 5 Ma BP and continues to this day. This process evolved geographically among the cordilleras of the region. Givnish and others recently presented phylogenomic evidence that the diversity of many epiphytic orchids, including tribes found in the neotropics, also accelerated during this time interval.. Phylogenetic investigations of tropical orchid pollinators have shown that acceleration in speciation in such pollinators as hummingbirds, orchid bees, and flies occurred over this same time frame, suggesting that geologically driven environmental changes may have acted in concert with changes in orchid biology to speed up orchid diversity in these highlands. I also review some of the long-distance dispersal processes of orchids in the tropical Americas. River systems draining the Colombian Andes discharge into the Caribbean Sea and current-driven log-raft drifts and air suspension during cyclonic storms transport plants and animals from east to the west. Lastly I emphasize the need for the more information on orchid floras and species distribution in this hotspot. 

Vanilloideae as currently circumscribed comprises nine genera and two tribes: Vanilleae and Pogonieae. The pantropical genus Vanilla has been frequently assumed to be natural on the basis of its climbing habit and lateral inflorescences. However, the inclusion of the rare Dictyophyllaria dietschiana in phylogenetic analyses makes the genus Vanilla paraphyletic. Within Pogonieae, phylogenetic analyses show that inclusion of Pogoniopsis turns the tribe paraphyletic. All analyses reveal that Pogoniopsis is closely related to members of Epidendroideae. Members of Pogonieae are pollinated by several groups of solitary and social bees, two pollination systems being recognized: reward-producing and deceptive. Molecular phylogeny suggests that the common ancestor to Pogonieae gave rise to two evolutionary lineages: one tropical with a condition of reward production; and one predominantly temperate-invading line with deceptive flowers. Reward-producing flowers characterize South and Central American clade (= Cleistes), while deceptive pollination is prominent in the clade including North American-Asiatic taxa plus Amazonian Duckeella. Species of “orchid bees” have been recorded as pollinators of the genus Vanilla (V. planifolia group and V. pompona group) in the Neotropics. In species of the V. pompona group, these bees are attracted by the fragrance of the flowers. Hummingbirds have been reported to pollinate some species of Vanilla. Vanilla insignis, V. odorata and V. planifolia are known to be pollinated through generalized food deception. Some species of Vanilla yield fruits through spontaneous self-pollination. This form of autogamy has been reported for V. griffithii, V. palmarum, V. planifolia, V. savannarum and V. bicolor. In Brazil, data on the pollination biology of Vanilla are scarce, but conclusive data are available for V. edwallii, which is pollinated by Epicharis (Apidae: Centridini). This species is rewardless, but male Epicharis are attracted to its flowers by their fragrance. Additionally, the Brazilian V. dubia and E. sclerophyllum are pollinated by bees. The mentum region of V. dubia and V. edwallii is dry, whereas that of E. sclerophyllum presents a small quantity of nectar. Flowers of E. sclerophyllum are scentless, while those of V. dubia are odoriferous. Vanilla dubia and V. edwallii are self-compatible and need a pollinator to yield fruits. In contrast, Epistephium sclerophyllum sets fruits through spontaneous self-pollination, but biotic pollination also occurs. Both species are primarily adapted to pollination by euglossine bees. Pollination by Euglossini seems to have evolved at least twice along the evolution of Vanilleae. Furthermore, shifts between rewarding and rewardless flowers and between autogamous and allogamous species have been reported among vanillas. 

El uso de herbicidas ha tenido un impacto grande sobre la producción agrícola y sin duda ha aumentado la producción en muchas cosechas. Desafortunadamente, la aplicación de herbicidas puede tener efectos negativos sobre otras especies nativas aledañas al cultivo. Con el fin de establecer si el herbicida glifosato afecta negativamente a la orquídea terrestre Epidendrum melinanthum y sus hongos endófitos aislados de la raíz, se evaluaron tres dosis de Round Up® en keikis y en hongos endófitos previamente aislados. Las dosis de aplicación se determinaron a partir de la utilizada para la maduración en caña de azúcar (1.5 l/Ha equivalentes a 544.5 g de glifosato/l) de la siguiente manera: a) control (sin herbicida), b) dosis de aplicación en caña de un décimo y c) una centésima parte de la dosis de maduración. Se observó en keikis el cambio de coloración en tallo y en hojas, adicional a la caída de las mismas. El Round Up generó afectación en uno de los tres hongos estudiados en forma de un halo de inhibición. Se concluye, que el glifosato afecta negativamente las estructuras foliares de los keikis de manera rápida al aplicar el herbicida sobre las hojas, en adición a la inhibición de un hongos endófitos de Epidendrum melinanthum. Estos aspectos sugieren el potencial negativo del herbicida sobre la especie estudiada y su microflora asociada. 

Catasetum is a neotropical orchid genus of 130 species characterized by its unisexual flowers. They are pollinated by male Euglossini bees. It is widely know that these bees collect volatile compounds in Catasetum from structures called osmophores. However, there is little information on morpho-anatomy and histochemistry of secretory tissues for this neotropical genus and data are lacking. Based on these arguments members of the Catasetum cristatum alliance, namely C. arietinum, C. ariquemense, C. barbatum, C. carolinianum, C. cristatum, C. lanciferum, C. multifidum, C. multifissum, C. rivularium and C. semicirculatum were analyzed. The labellum of male flowers of this alliance is elongate and with fimbriate margins, possessing two protuberances and a median saccate portion. The labellum of female flowers is galeiform and there is no ornamentation. The entire adaxial surface of the labellum is secretory in both sexes, including the fimbriae of male flowers. The structure of the secretory tissue is similar among species, and they are composed of a simple epidermis and five layers of underlying parenchyma. In most species the epidermis is flat, and cells are elongated in the saccate portion. In C. ariquemense and C. carolinianum the epidermal cells are papilous, while in C. semicirculatum they have convex surface (male flowers). The histochemical analysis detected lipophilic droplets and starch grains inside the secretory cells. All characteristics observed are encountered in secretory tissues with high-energy demand, as is common in osmophores. 

Orchids are a main component of the diversity of vascular plants in Ecuador with approximately 4000 species representing about 5.3% of the orchid species described worldwide. More than a third of these species are endemics. As orchids, in contrast to other plants, depend on mycorrhizal fungi already for seed germination and early seedling establishment, availability of appropriate fungi may strongly influence distribution of orchid populations. It is currently debated if green orchids depend on specific mycobionts or may be equally promoted by a broad spectrum of mycorrhizal fungi, discussion mostly based on data from temperate regions. Here we summarize results obtained from broad scale investigations in the tropical mountain rain forest of Ecuador revealing associations with members of Serendipitaceae (Sebacinales), Tulasnellaceae, Ceratobasidiaceae (Cantharellales), and Atractiellales. Recent molecular data show that these worldwide spread fungal groups have broad ecological implications and are specifically suited as mycorrhizal fungi of green orchids. We found that main fungal partners and different levels of specificity among orchids and their mycobionts in the tropical mountain forests correspond to findings in other biomes despite the large ecological differences. 

Taxonomic work has been historically regarded as a two-fold discipline. The first, which is basically aimed at answering the question about the diversity in whatever group under study, includes most of the “biological” questions of the research. Understanding of genetic and morphological variation, structure of populations and life cycles, biogeography and phylogeography, ecological modeling, pollination and other biological components is required to define the relationships among the taxa of the group and eventually to describe their diversity. The second part of the work consists in applying a correct name to all of the organisms as they result from the biological work. This second step is usually interpreted as the documentary component of the research, and in fact it mostly deals with the document sources and the rules of biological nomenclature (such as protologues, types and other historical materials associated with the type collections, etc.). However, the use of nomenclatural sources with little or no consideration for the biological aspects of the concerned organisms can be misleading, and the same concept of “type” can be hardly understood if not framed in a rich biological context. Type specimens are just random, individual samples that must be interpreted in the context of the geographical and biological integrity of any given species, and this requires at least some direct knowledge of the organisms and their biology. When the geographical origin of type specimens lies outside the political boundaries of a given study area, taxonomic research is seriously hampered by the impossibility to visualize and understand them in a biological framework. A specific case from the research intended to complete the treatment of the Orchidaceae for the flora of Costa Rica will exemplify how a cooperative approach based on a shared methodology may be the only way to resolve the taxonomy of complex species. 

Area and latitude are thought to be the most important determinants of species richness. The relative importance of these two factors was recently tested, using data on orchid species diversity in various countries in the world and it was found that size of the country (or of the protected areas within the country) is a better determinant of species diversity in orchids than latitude. On the other hand, literature data indicate that in many groups species richness is also heavily dependent on habitat diversity as expressed by the range of altitudes in the region considered. Here we analyze the species richness data for various countries in Latin America, using the above-mentioned altitudinal amplitude as a proxy. Habitat diversity played a role in tropical, but not in temperate countries. The reason may indicate that in the temperate countries only few orchid species grow in higher elevations, so an increase of altitudinal range of habitats there does not entail a corresponding increase of species richness there. Thus, especially in the tropics, efforts should be directed to preservation of protected areas in all altitudes, rather than to increase of existing reserve size only in areas that are not attractive for human development.