Current and expected changes in global climate are major threat for biological diversity affecting individuals, communities and ecosystems. However, there is no general trend in the plants response to the climate change. The aim of present study was to evaluate impact of the future climate changes on the distribution of holomycotrophic orchid species using ecological niche modeling approach. Three different scenarios of future climate changes were tested to obtain the most comprehensive insight in the possible habitat loss of 16 holomycotrophic orchids. The extinction of Cephalanthera austiniae was predicted in all analyses. The coverage of suitable niches of Pogoniopsis schenckii will decrease to 1–30% of its current extent. The reduction of at least 50% of climatic niche of Erythrorchis cassythoides and Limodorum abortivum will be observed. In turn, the coverage of suitable niches of Hexalectris spicata, Uleiorchis ulaei and Wullschlaegelia calcarata may be even 16–74 times larger than in the present time. The conducted niche modeling and analysis of the similarity of their climatic tolerance showed instead that the future modification of the coverage of their suitable niches will not be unified and the future climate changes may be not so harmful for holomycotrophic orchids as expected.

This micromorphological, chemical and ultrastructural study is a continuation of research conducted on the section Lepidorhiza. The Bulbophyllum echinolabium flowers comprised features that characterize a sapromyophilous syndrome, having large, glistening parts that emit an intense scent of rotten meat. The secretory activity was described in the hypochile (nectary in longitudinal groove and in the prickles) and the epichile (putative osmophore). The ultrastructural studies revealed a dense cytoplasm in the epidermis and subepidermal tissue with large nuclei and numerous mitochondria, the profiles of SER and RER, and dictyosomes. Large amounts of heterogeneous residues of secreted material (possibly phenolic) were present on the cuticle surface, similar to the unusual prominent periplasmic space with flocculent secretory material. The chemical analysis (GC/MS) of the scent profile of lips comprised carbohydrates and their derivatives (29.55% of all compounds), amino acids (1.66%), lipids (8.04%) and other organic compounds (60.73%). A great number of identified compounds are Diptera attractants (mainly Milichiidae, Tephritidae, Drosophilidae, Muscidae, Sarcophagidae, Tachinidae). The examination of visual and olfactory features indicates correlation between colour of flowers and the type of olfactory mimicry, where a dark colour labellum emits strong smell of rotten waste.

Masdevallia Ruiz. & Pav. in the broad concept comprises about 350 species distributed from southern Mexico to southern Brazil with the highest diversity in the Andes of Ecuador and Colombia, Peru, and Bolivia. Until now, only six species have been found in Guatemala. While studying the diversity of the orchid flora in this megadiverse country, we came across plants that in terms of morphological characteristics, were intermediate between M. floribunda Lindl. and M. tuerckheimii Ames. All three taxa are pollinated by two so far undescribed species of Zygothrica fruit flies. In the presented work, we describe the new entity as a new natural hybrid. This is the first record of the hybridization within the genus Masdevallia from Guatemala.

This literature review aims to synthesise existing knowledge on research on pollination of orchid species in Guatemala. Orchids, known for their diverse and specialised interactions with pollinators, play a key role in the ecosystems of this Central American country. As a base for our research, we have used the orchid checklist published in 2018 where more than 1200 taxa have been listed. Then we conducted a systematic search of academic databases, including, but not limited to PubMed, Web of Science, Scopus and relevant botanical databases. From 1231 orchid species reported to occur in Guatemala and classified in 221 genera, we have found data on pollination of only 98 taxa, classified in 71 genera. Through an exhaustive survey of the relevant scientific literature, this review intends to provide a comprehensive summary of the available data, highlighting gaps in current knowledge and suggesting directions for future research. Research on pollination in tropical orchids presents a formidable challenge due to the immense diversity of species, the intricacies of pollination mechanisms, the elusive nature of pollinators and the susceptibility of these ecosystems to environmental changes. Despite these challenges, the importance of unravelling these mysteries is underscored by the critical role orchids play in tropical ecosystems and their potential implications for conservation and biodiversity.

Crepidium is a large genus of mainly pantropical orchids. The lips of its flowers are upwardly directed and do not serve as landing platforms for pollinators. This role is assumed by the dorsal sepal and/or gynostemium. Information about the pollination and floral morphology of this genus is scarce. To date, no papers have been published on these topics. Field observations have revealed that the flowers are visited by small flies, midges, fruit flies, other small dipterans, ants, spiders, and mites. Preliminary observations revealed at least two forms of small liquid droplets secreted on the lip surface of Crepidium species: simple secretions from epidermal cells, and cell sap released upon the rupturing of raphide-producing cells. Further research revealed that this was the first time liquid secretion was recorded in this genus. Floral secretions were subjected to sequential organic solvent extraction and gas chromatography–mass spectrometry (GC–MS). Floral parts were investigated by means of scanning (SEM) and transmission electron microscopy (TEM), and histochemical tests. The presence of liquid droplets on the lip of Crepidium, the presence of a food reward, and the sequence of raphide development are reported here for the first time.

Neotropical genus Maxillaria Ruiz & Pav. belongs to one of the most diverse and species-rich groups of orchids. Several of its representatives are popular, horticultural plants with large and showy flowers, often nicely fragranced. It is not uncommon that some distinctly colored individuals are introduced to the commercial market under names of similar, more or less related species, as informal varieties or color forms, largely causing confusion. While investigating the diversity of Maxillaria in Ecuador, we have encountered plants that were commercially referred to as M. sanderiana xanthina. In the course of conducted morphological and micromorphological analyses, we concluded that it is a new, separate species and hereby, we describe it as M. anacatalinaportillae.