Nectar gain and loss are important flower transitions observed in angiosperms, and are particularly common in orchids. To understand such transitions, the availability of detailed anatomical data and species-level phylogenies are crucial. We investigated the evolution of food deception in Epidendrum, one of the largest orchid genera, using genus phylogeny to map transitions between nectar gain and loss among different clades. Associations between anatomical and histochemical changes and nectar gain and loss were examined using fresh material available from 27 species. The evolution of nectar presence/absence in Epidendrum species was investigated in a phylogenetic framework of 47 species, using one nuclear and five plastid DNA regions available from GenBank and sequenced in this study. The presence or absence of nectar was strongly associated with changes in the inner epidermal tissues of nectaries. Nectar-secreting species have unornamented epidermal tissue, in contrast to the unicellular trichomes found on the epidermis of food deceptive species. Bayesian tests confirmed that transitions occurred preferentially from nectar presence to nectar absence across the Epidendrum phylogeny. In addition, independent nectar loss events were found across the phylogeny, suggesting a lack of constraint for these transitions. Ornamented nectaries may play an important role in the deceptive pollination strategy by secreting volatile organic compounds and providing tactile stimuli to pollinators. The recurrent and apparently irreversible pattern of nectar loss in Epidendrum suggests that food deception may constitute an alternative evolutionarily stable strategy, as observed in other orchid groups.

In this study, we analyse a species complex in Epidendrum, a mega-diverse Neotropical orchid genus, that is formed by the 11 Brazilian species of the E. difforme group. Although this group (c. 100 taxa) exhibits relatively high levels of floral variation, the Brazilian species are similar, making delimitation problematic. Here we combine molecular (phylogenetics), morphological (geometric morphometrics), genome size and cytogenetic (chromosome counts and CMA/DAPI staining) data to investigate circumscription of these species. Our results were interpreted by looking for congruence of the results as a means to delimit species. The studied taxa appear to be monophyletic, and karyotypically all analysed accessions were 2n = 40. Their 1C values vary from 1.99 ± 07 pg to 2.84 ± 0.12 pg. We did not find evidence for recent polyploidy or dysploidy and, apparently, these phenomena have not been important in the evolution of this species complex. On the other hand, we found high levels of polymorphism for CMA/DAPI banding, and variation in genome size appears to be positively correlated with latitude. Geometric morphometrics indicate that E. sanchezii and E. anatipedium/E. amarajiense are distinct from the remaining species, and three groups of other species can be separated using canonical variables analysis (CVA). Variation in lip shape, genome size and heterochromatin patterns of the taxa are not fully congruent with the phylogenetic analysis, but our results allowed us to delimit with full confidence four species: E. amapense, E. anatipedium (including E. amarajiense), E. pseudodifforme (including E. campaccii and E. thiagoi) and E. sanchezii. Four others will be tentatively maintained but need further study. Our results indicate that it will be necessary to reassess many of the species complexes in the genus using a similar multidisciplinary perspective to evaluate the number of taxa that should be recognized.

Sixteen species of Costus s.s. are cited to Brazil, all of which can be found in the Brazilian Amazon, while only three also grow in the Atlantic Forest: C. arabicus, C. scaber, and C. spiralis. Studies of the genus from the Brazilian Atlantic Forest evidenced a distinctive fourth taxon, similar overall to C. spiralis, which is an ornithophilous species, however the flower morphology of this new taxon indicates it to be melittophilous. Hybridization and polyploidy (allopolyploidy or autopolyploidy) may play a role as an important source for evolutionary events, especially in recent speciose lineages such as Neotropical Costus. Here we investigated the evolutionary origin of this interesting Costus species using an integrative approach. This approach comprised a morphological analysis, cytogenetic analyses (chromosome counts, CMA/DAPI staining, and fluorescent in situ hybridization), genome size estimations, and a molecular phylogenetic reconstruction (using the plastid regions rps16 and trnL-F, and the nuclear ITS and ETS), aiming to answer the following questions: is it a hybrid?; is it an autopolyploid of C. spiralis?; or, if it is a different species, is it even phylogenetically related to C. spiralis or C. arabicus? The studies performed did not indicate any evidence of polyploidy, however, a chromosomal polymorphism was observed between the populations of the taxon studied. The phylogenetic position of this peculiar taxon with C. erythrophyllus, C. spiralis, and C. varzearum also excludes the putative partial heritage of C. arabicus which had been previously hypothesized. Our results confirm that it is a new, undescribed species, which is confirmed by our morphological observations of floral features. A complete taxonomic treatment of the new species is provided, including a key for the species of the genus in the Atlantic Forest.

Orchidaceae foi citada recentemente como a família mais representativa na Floresta Atlântica. Considerando essa representatividade, a fragmentação com perda de diversidade e a carência de informações para a área, este trabalho inventariou a flora orquidológica em remanescentes florestais na Usina São José (USJ), Pernambuco, Brasil. O estudo foi realizado em seis fragmentos na mata Norte Pernambucana, localizados no município de Igarassu. Foram realizadas expedições mensais de dezembro de 2008 a março de 2010. As amostras foram depositadas no herbário UFP. Orchidaceae está representada na área por 27 espécies e 19 gêneros, cujos mais representativos foram Epidendrum (4 spp.) e Scaphyglottis (3 spp.). Incrementa-se 20 spp. àquelas citadas para a USJ em lista anterior. Três espécies foram citadas pela primeira vez para a Floresta Atlântica, sendo uma um novo registro para flora nordestina. Cattleya granulosa Lindl. e Zygostates bradei (Schltr.) Garay estão incluídas em listas de espécies ameaçadas de extinção na categoria de vulneráveis. O fragmento Piedade merece destaque por apresentar 26 spp., sendo este uma RPPN. Os dados reforçam a importância da área para conservação da biodiversidade no estado.

Subtribe Angraecinae (Orchidaceae: Vandeae) are mainly distributed in Africa, but with two genera, Campylocentrum and Dendrophylax, restricted to the Neotropics. As a widespread Neotropical genus, Campylocentrum constitutes an appropriate model for revealing biogeographical patterns in this area and investigating routes of colonization and dispersal. In this study, we reconstructed phylogenetic relationships of the genus with Bayesian inference and maximum parsimony analyses of combined nuclear (ITS rDNA and Xdh) and plastid (matK exon, rpl32-trnL spacer, trnL intron, trnL-trnF spacer and ycf1 exon) DNA datasets, aimed at establishing a new infrageneric classification for this taxonomically complex genus. Based on the most comprehensive phylogenetic tree, we investigated the biogeographical history of Campylocentrum by estimating divergence times, inferred using fossil and secondary calibrations applying a relaxed-clock model approach, and reconstructing ancestral areas of distribution under a time-stratified likelihood model. The phylogenetic analyses provided strong support for the majority of the clades. Campylocentrum is monophyletic, and we recognize five sections based upon strongly supported clades. We conclude that the African angraecoid ancestor of Campylocentrum and Dendrophylax dispersed to the Antilles. Campylocentrum is estimated to be a relatively young genus (late Miocene, c. 8.2 Mya) and its most recent common ancestor had a disjunct distribution in the Antilles and Parana dominion. During the Pliocene, the five sections diverged and expanded their distributions in the Neotropics, and in the Pleistocene diversification was experienced by some of the terminal clades. We hypothesize that the evolutionary history of Campylocentrum was strongly influenced by orogenic events during the Pliocene and climatic fluctuations during the Pleistocene.