Joanna Mytnik-Ejsmont

Taxonomy of the Subtribe Maxillariinae (Orchidaceae, Vandoideae) revised

Abstract A new classification of the subtribe Maxillariinae (Orchidaceae) is proposed. Thirty-seven genera are revised. The Camaridium group is divided into seven genera, Adamanthus, Camaridium, Pseudomaxillaria, Psittacoglossum and three described here: Chaseopsis, Chelyella and Viracocha. Ornithidium s.l. is divided into seven genera: Heterotaxis, Laricorchis,Neo-urbania, Nitidobulbon, Ornithidium, Vazquezella and Aucellia, the latter two described here. 193 new combinations on the species level are validated and the relationships among the genera are briefly discussed. A key to the determination of all genera representing Maxillariinae s. s. is provided.

Reclassification of the Angraecum-alliance (Orchidaceae, Vandoideae) based on molecular and morphological data

Abstract Results of molecular analysis compared with morphological studies were used for reclassification of the Angraecumalliance (Orchidaceae). For the purpose of this study we sequenced the ITS region (ITS1-5.8S-ITS2) of nrDNA representing nuclear genome and the plastid region trnL-F (including intron of trnL gene and trnL-trnF intergenic spacer). The ITS matrix includes 97 samples representing 86 species and the trnL-F matrix includes 94 samples representing 86 species. We focus mainly on the genus Angraecum, however the other genera of Angraecinae are also included (Aeranthes, Campylocentrum, Dendrophylax, Cryptopus, Calyptrochilum, Lemurorchis, Jumellea, Neobathiea, Oeonia, Oeoniella, Sobennikoffia). Additional 43 sequences, including an outgroup (Polystachya modesta) and other representatives of the subtribes Aeridinae (Aerides) and Aerangidinae (Aerangis, Angraecopsis, Erasanthe, Solenangis), were obtained from NCBI resources. Bayesian analysis using MrBayes 3.1.2 on the combined ITS/trnL-F matrix were performed. The monophyly of Angraecinae with an inclusion of Aerangidinae is highly supported by both methods (93 BP/100 PP). The Angraecoid taxa formed two well supported clades, namely clade I (89 BP/100 PP) and clade II (84 BP/100 PP). New classification based on both molecular and classical taxonomy studies is presented including a key to the genera. The subtribe Angraecinae includes 36 genera, 18 of them, included within Angraecum by different authors so far, are treated here. Five new genera are described: Eichlerangraecum, Hermansia, Lesliegraecum, Pectianriella and Rudolfangraecum. Ten sections of Angraecum are raised to the generic status.

Phylogenetic Placement and Taxonomy of the Genus Hederorkis (Orchidaceae)

Three plastid regions, matK, rpl32-trnL and rpl16 intron and the ITS1-5.8S-ITS2 nuclear ribosomal DNA were used to demonstrate a phylogenetic placement of the genus Hederorkis (Orchidaceae) for the first time. The taxonomic position of this genus has been unclear thus far. The phylogenetic and morphological relations of Hederorkis to the most closely related genera Sirhookera, Adrorhizon, Bromheadia and Polystachya are also discussed. A hypothesis concerning an origin and evolution of Hederorkis is proposed. Hederorkis is an epiphytic two-leaved orchid genus with lateral inflorescence, non-resupinate flowers, elongate gynostemium and rudimentary column foot. It is native to the Indian Ocean Islands. Two species of Hederorkis are recognized worldwide, H. scandens endemic to Mauritius and Réunion and H. seychellensis endemic to Seychelles. For each of the species treated a full synonymy, detailed description and illustration are included. The distribution map and dichotomous keys to the species have also been provided.

Taxonomic Position and Phylogeny of the Genus Vargasiella (Orchidaceae, Vandoideae) Based on Molecular and Morphological Evidence

Since the description of the Neotropical genus Vargasiella in 1952, its taxonomic position has remained unclear, mainly due to a lack of sufficient data. In this study, the taxonomic position of Vargasiella was revised based on the outcomes of macro- and micromorphological studies, analyses of selected molecular markers and ecological methods of niche distribution modeling. The phylogenetic relationships were inferred using three DNA markers: matK, trnL-F and ITS sequences. The morphological studies included the analysis of macromorphological features of herbarium specimens as well as micromorphological examination of preserved flowers. The ecological niche modeling was applied to identify the distribution of the suitable niches of the studied taxa. The relationships between Vargasiella and most similar taxa remain unresolved based on the molecular analysis. The outcomes from the morphological studies indicated significant differences between Vargasiella, Warrea and Warreopsis. Moreover, a niche shift in response to changing climate after the last glacial maximum is observed in Vargasiella, while no substantial changes in the occupied habitats were identified in the other related taxa. The clocktree of the Zygopetaleae estimated from the matK gene indicated that the most recent common ancestors of Vargasiella, Warrea and Warreopsis originated in the Miocene, while the divergence time for Vargasiella and Warrea was assessed at approximately 5.4 Ma ago. Vargasiella seems to be an outshoot of the main branch of evolution of the Zygopetaleae. It is noteworthy that the Vargasiella-Warrea dichotomy could have taken place later than the divergence of Warreopsis from the mutual lineage. The molecular analysis and morphological data suggest that Vargasiella and Warrea could have evolved from a common ancestor. Accumulation of morphological differences and acceleration of the evolution of Vargasiella were more intensive than in other Warreinae and this could probably be synchronized with adaptation to different climatic conditions.

Revision of the Genus Myrosmodes (Orchidaceae, Spiranthoideae) in Colombia

Abstract Descriptions, brief taxonomic notes, and data on the ecology of the Colombian Myrosmodes species as well as a key for determination of all species known from the northern Andes are provided. The descriptions are complemented by illustrations and maps of their distributions.

A phylogenetic and morphological study of Polystachya sect. Superpositae (Orchidaceae) with description of a new species from Cameroon

Polystachya section Superpositae is a group of montane and submontane African epiphytes with thirteen species (including the newly described in this paper). During a scientific expedition to Bamenda Highland, Cameroon a new species, Polystachya bamendae, was found and it is described here. The new entity was compared with 398 herbarium specimens representing the section, including the type collections. The molecular analyses of the ITS and matK strongly support the results of morphological studies and reveal close relationship between the new species and the species of the section Superpositae. Two hypotheses supporting function of the matK gene in the examined species are presented. The phylogenetic and morphological relation of Polystachya bamendae to P. lindblomii and P. superposita is discussed. The distribution range of the section is analyzed and a discussion about the distribution of the species is presented. A distribution map of the section and dichotomous key to the species of Superpositae are provided. The occurrence of the species of the section in two Biodiversity Hotspots (Guinea Forests of West Africa and Eastern Afromontane) is discussed.

New species of the genus Epistephium (Orchidaceae, Vanilloideae)

The morphological study of the herbarium material representing Epistephium (Orchidaceae, Vanilloideae) led to the discovery of two groups of specimens that significantly differ from all known species of the genus. The results of literature data study and of comparative analysis of those and other specimens suggest that these collections represent new taxa that we describe as E. garayi and E.kubiyuense. The distinguishing features of the species are indicated. As both new species are reported from Colombia (E. garayi, also from Guyana), the key for the determination of all Colombian representatives of the genus is included. Information on the ecology and distribution of newly described taxa is presented.

Chelystachya, a new genus of the subtribe Polystachyinae (Orchidaceae)

Chelystachya, a new genus of the subtribe Polystachyinae (Orchidaceae) A new genus of Orchidaceae (Polystachyinae), Chelystachya Mytnik & Szlach. is described and illustrated basing on results of molecular and morphological studies. It is related to Polystachya Hook. but is distinct in having large, single-noded, spherical, succulent pseudobulbs flattened on the substratum, pendent and densely pubescent inflorescence, lowermost lip, and lip veins directed to the lip base. Results of phylogenetic analyses based on plastid markers validate the reason for a new genus. Keys for determination of all genera of the subtribe Polystachyinae and both species of Chelystachya are included. Two new combinations are made. A comprehensive description and full synonymy, as well as detailed ecological, phenological and distribution data and a list of 125 examined specimens are provided for each taxon treated. Because Polystachya affinis Lindl. is considered a holotype of Polystachya Hook. sect. Affines Kraenzl., this name is automatically a synonym of the newly introduced generic name Chelystachya. Other species of the former section Affines are classified within the section Humiles.

Two new species of Polystachya Hook. (Orchidaceae) from Africa

Two new species of Polystachya Hook. are described and illustrated: Polystachya rydingii Baranow & Mytnik occurring from the Democratic Republic of Congo and P. sosefii Baranow & Mytnik from Cameroon. The species belong to the section Polystachya Kraenzl., which is the only pantropical section in the genus. Maps of the distribution for the new species and their closest relatives and a brief discussion with notes on their habitat, ecology, and altitude are provided.

Eight new species of Gomphichis (Orchidaceae, Spiranthoideae) from Colombia

Eight new species of the genus Gomphichis from Colombia are described. Each species is illustrated, and detailed habitat and distribution data are provided. A distribution map of the new species is presented. A dichotomous key for determination of the Gomphichis species in northern South America is provided. Conservation status assessments are provided for each species; current International Union for Conservation of Nature (IUCN) Red List categories and criteria are listed. A brief discussion of spiranthoid orchids taxonomy, conservation status of species, endemism in the Andes and paramo are presented.