Previous studies have shown that the ultrastructure and histochemistry of flowers give insight into the pollination mechanisms of orchid species. The microscopic features of species within the Pleurothallidine subtribe are poorly understood. In this study, we investigated three Lepanthes species: L. calodictyon, L. saltatrix and L. tentaculata. These species have a similar flower morphology that is distinct from that of the other representative of the genus. Our analyses revealed the presence of features usually associated with myophily. The papillae of lips and petals of the L. calodictyon group were rich in lipids and proteins, which were correlated with high metabolic activity. Furthermore, the ultrastructural and morphological features were similar to those observed in other fragrance-emitting orchid species. Histochemical, ultrastructural and morphological features of the papillae on the surface of the lips and petals of examined taxa indicate that the papillae are osmophores.

Pleurothallopsis renziana sp. nova (Orchidaceae) is described based on Venezuelan material. It resembles R microptera in which, however, the sepals are longer, the dorsal sepal is oblong-ovate, somewhat constricted in apical third, the lip is widest in the apical third, with small lateral lobes, and ornamented exclusively with one pair of low calli. The flower morphology of P renziana resembles that of P tubulosa, but the former differs from the latter by the larger plant size and longer leaves, obliquely linear-ovate lateral sepals, petals being widest in the basal third or in the middle, lip being distinctly wider across lateral lobes than across middle lobe, convex basal part of lip, presence of a pair of low calli extending from the lip lateral lobes' base, and an additional keel running along the central part of the lip.

A new species of Acianthera from Brazil is described and illustrated here. The novelty belongs to the nominal subgenus of Acianthera and it resembles Acianthera hystrix and A. portilloi but it is easily distinguishable by the external and internal pubescence of the sepals, the pubescent ovary and the lip disc ornamented with three lamellae. A dichotomous key to identification of all known species of Apoda-prorepentia group is provided.

The purpose of the study was to determine the chemical composition of extracts from three species of orchids: Brasolia cattleya, Elleanthus oliganthus and Sobralia powellii, all belonging to the Sobralieae tribe, evaluate their antistaphylococcal activity and assess possible toxicity towards eukaryotic cells on the model organism Caenorhabditis elegans. The chemical composition of the methanolic extracts from those plants was tested with the use of UHPLC-ESI-MS/MS method. The phytochemical analyses of the extracts revealed presence of three main groups of secondary metabolites: phenolic derivatives, flavonoid glycosides and triterpenoid saponins. In our studies, the presence of C-O-glycosides of methoxylated flavones and ester derivatives of arbutin were found for the first time in the Orchidaceae family. The extracts were investigated for antimicrobial activity against five Staphylococcus aureus strains, including four strains isolated from hospital patients. The antimicrobial activity of the orchid extracts was estimated by the Minimum Inhibitory Concentration (MIC) and the Minimal Bactericidal Concentration (MBC) determined by Broth Microdilutions method. All of the examined extracts showed strong antimicrobial activity against the S. aureus strains. The MBC values ranged from 0.25 to 0.75 mg of fresh weight (fw)/mL. To assess the toxicity of the extracts we used cultures of C. elegans, wild-type N2 Bristol strain. The extracts occurred to be nontoxic towards C. elegans in a broad range of concentration (from 0.75 mg to 50 mg fw/mL) after 24-hour incubation. The maximum extract dose tested on C. elegans was 10 times higher than the effective bactericidal concentration for S. aureus. The obtained results allow us to conclude that the methanolic extracts from B. cattleya, E. oliganthus and S. powellii are of a potential use for treatment of bacterial infections caused by the antibiotic-resistant strains of S. aureus.

Trichosalpinx carinatus Rykaczewski, Szlach. & Kolan. (Orchidaceae) of the T. dependens complex is described and illustrated as a new species from Colombia. It is easily distinguishable from similar species by its unique, glabrous sheaths of the rami-caul as well as by the presence of a six-veined synsepal and an entire callus on the lip. Keys to identification of representatives of T. dependens complex and to Colombian Trichosalpinx are provided.

Two new species of the orchid genus Brachionidium are described and illustrated based on Colombian material. Both novelties are relatively large, stout and erect plants characterized by the presence of a glabrous callus lip. Brachionidium elzbietae sp. nov. resembles B. tuberculatum from which it differs by the long‐tailed sepals and lip lacking a glenion. Brachionidium dorisiae sp. nov. is similar to B. fornicatum, but is easily distinguished by its larger and shortly bifid synsepal. A key to identification of Colombian representatives of Brachionidium is provided the morphology of new species and their relatives is compared.

Trichosalpinx ollgaardiana Rykaczewski, Kolan. & Szlach. (Orchidaceae) is described and illustrated as a new species from Ecuador and placed in the subgenus Trichosalpinx. It is similar to T. crucilabia and T. quitensis, from which it differs by long-connate lateral sepals, ligulate-spathulate petals with irregular apical margins, a prominent lip claw, and a ventral anther. An identification key to Ecuadorian representatives of Trichosalpinx subgenus Trichosalpinx is provided.

The distribution patterns of Neotropical orchid genus Diodonopsis were analysed and the location of its glacial refugia was reconstructed. The possible changes in the coverage of suitable niches of Diodonopsis representatives were evaluated using three different scenarios. The results of ecological niche modeling indicated that the range of studied taxa is in regression since last glacial maximum. The climatic niches of three Diodonopsis species are well separated.

A new species of Lepanthopsis is described and illustrated based on Peruvian material. Lepanthopsis bennettii is similar to L. dewildei from which it differs by long-connate lateral sepals, broadly ovate dorsal sepal, large lip basal lobes and petals form. Phylogenetic placement of the new species as well as identification key and comparative morphology of all known representatives of Lepanthopsis with single-flowered inflorescence are presented.

Elleanthus albiflorus (Orchidaceae) is described and illustrated based on Peruvian material. The novelty resembles E. flavescens from which it can be easily distinguished by the white flowers, flabellate lip and presence of lip calli with prominent outgrows. A key for identification of all Peruvian species of Elleanthus with branching stems is provided.

A new species of Lepanthes is described and illustrated based on the material collected during field work in Guatemala. Lepanthes swartzii is similar to L. pantomima Luer & Dressler and L. arachnion Luer & Dressler from which it differs by 1-veined petals, lip with incurved basal lobes and obtuse apex, and by circular leaves with smooth margins. Identification key to all known Guatemalan species of Lepanthes with reticulated leaves is provided.

A new species of Elleanthus, E. ortizianus, discovered among Colombian material, is described and illustrated. The novelty resembles Elleanthus bifarius Garay, from which it differs by loose floral bracts, externally furfuraceous sepals, sharply acute apically petals and shape of the lip as well as by the presence of a fleshy ridge between the basal cavity and lip blade. Comparative morphology of E. bifarius and the new species is presented.

Abstract This paper presents new records of 135 lichen taxa in Bolivia. Two species, Myriotrema laeviusculum (Nyl.) Hale and Graphis tenoriensis Chaves & Lücking, are new for the Southern Hemisphere; two, Cladonia uncialis (L.) Weber ex F. H. Wigg. and Thelocarpon laureri (Flot.) Nyl., are new for South America; and 27 species are new for Bolivia: Acanthotrema brasilianum (Hale) Frisch, Bulbothrix laevigatula (Nyl.) Hale, B. leprieurii Aubel, Canoparmelia salacinifera (Hale) Hale, Catolechia wahlenbergii (Flot. ex Ach.) Körb., Chapsa alborosella (Nyl.) Frisch, Coccocarpia dissecta Swinscow & Krog, Graphis apertoinspersa Rivas Plata & Lücking, G. cinerea Fée, G. globosa (Fée) Spreng., G. haleana R. C. Harris, G. marginata Raddi, G. pilarensis Cáceres & Lücking, G. striatula (Ach.) Spreng., Hemithecium oryzaeforme (Fée) Staiger, Hypotrachyna protochlorina Sipman, Elix & T. H. Nash, H. sinuosella Elix, T. H. Nash & Sipman, H. tariensis Elix, Parmeliella isidiopannosa Jørg., Parmotrema conferendum Hale, P. enteroxanthum Hale, P. laciniellum (Ferraro & Elix) Blanco et al., P. pilosum (Stizenb.) Krog & Swinscow, P. recipiendum (Nyl.) Hale, P. ruptum (Lynge) Hale ex DePriest & Hale, Pyxine pungens Zahlbr. and Xanthoparmelia substenophylloides Hale. Notes on distribution are provided for the species. Bulbothrix goebelii (Zenker) Hale is excluded from the list of Bolivian lichens; the record is referred to B. laevigatula.

A new species of Pleurothallis subsect. Antenniferae Luer is described and illustrated based on Colombian material. The taxonomic affinity of the novelty is briefly discussed. An updated key for identification of Colombian representatives of P . subsect. Antenniferae is presented.

The present study aimed to evaluate the possible relationship between the changes in hydrogen peroxide (H2O2) and nitric oxide (NO) content and the course of growth and reproductive processes of the cell cycle of Chlamydomonas reinhardtii. The peak of H2O2 observed at the beginning of the cell cycle was found to originate from Fe-SOD and Mn-SODchl. activity and result from the alternation in the photosynthetic processes caused by the dark-to-light transition of daughter cells. A rapid increase in NO concentration, observed before the light-to-dark cell transition, originated from NR and NIR activity and was followed by a photosynthesis-independent, Mn-SODchl.-mediated increases in H2O2 production. This H2O2 peak overlapped the beginning of Chlamydomonas cell division, which was indicated by a profile of CYCs and CDKs characteristic of cells’ passage through the G1/S and S/M checkpoints. Taken together, our results show that there is a clear relationship between the course of the Chlamydomonas cell cycle and typical changes in the H2O2/NO ratio, as well as changes in expression and activity of enzymes involved in generation and scavenging of these signaling molecules.

In a study of the Xanthoparmelia species containing usnic acid in Poland, six taxa have been recognized. Xanthoparmelia plittii is new to Poland. Some of the material is referred to as X. aff. cumberlandia. Xanthoparmelia conspersa is the most common species of the group in Poland (c. 67 % of all records). Xanthoparmelia angustiphylla is widespread, but less common (c. 20 % of all records). The remaining Xanthoparmelia taxa in Poland, i.e. X. aff. cumberlandia, X. mougeotii, X. plittii and X. stenophylla, are rare or very rare in the country. The distribution and threat status of all taxa, their habitat requirements, morphology and secondary chemistry are discussed and notes on similar taxa are made.