Cheirostylis seidenfadeniana sp. nov. (Orchidaceae) from India

Cheirostylis seidenfadeniana is described from Kerala in India. The new species appears to be related to C. parvifolia and shares some characteristics with C. thailandica and C. montana , but differs in floral characters.     

Crossoglossa frontinoensis sp. nov. (Orchidaceae,Malaxideae) from Colombia

A new species of the genus Crossoglossa, C. frontinoensis Szlach. & Kolan. sp. nov., is described and illustrated based on Colombian material. The new species appears to be similar to Crossoglossa tipuloides, but it is easily separable by distinctly narrower lip with pandurate basal part and long‐acuminate apical part, much narrower, long‐acuminate sepals and petals and narrower leaves. Information about its habitat, ecology and distribution is provided.     

Cephalanthera humilis sp. nov. (Orchidaceae) from Yunnan,China

Cephalanthera humilis X. H. Jin, a new species from Yunnan, China, is described and illustrated. The new species is closely related to C. calcarata but differs from it by having an entire lip without spur at base and the stigma on top of the column.     

Neottia chandrae sp. nov. (Orchidaceae) from Nepal

Neottia chandrae B. B. Raskoti, J. J. Wood & Rita Ale sp. nov. is described and illustrated from Nepal. Notes on the diagnostic characters used to distinguish it from allied species are provided.     

Gastrodia sui sp. nov. (Orchidaceae) from Taiwan

A new orchid species, Gastrodia sui C. S. Leou, T. C. Hsu & C. L. Yeh is described and illustrated from Taiwan. The new species is closely related to G. callosa J. J. Sm. but distinguishable by the number and position of calli inside the perianth tube, the fused ratio of perianth lobes, and the structure of the lip and column. It is so far only found in the area of Mt Lilung in southern Taiwan.     

Sarcoglyphis manipurensis sp. nov. (Orchidaceae) from Manipur,India

A new orchid species, viz. Sarcoglyphis manipurensis, is described and illustrated from Imphal east and Chandel districts of Manipur in northeast India. It's distinguishing characters and affinity with S. mirabilis (Rchb.f.) Garay is discussed. An updated artificial key to all known species of Sarcoglyphis is provided.     

Dendrobium shixingense sp. nov. (Orchidaceae) from Guangdong,China

Dendrobium shixingense Z.‐L. Chen, S.‐J. Zeng et J. Duan sp. nov. (Orchidaceae), is described and illustrated from Guangdong, China; it is compared with its nearest allies, D. scoriarum, D. flexicaule and D. officinale.     

Microstylis schneideri sp. nov. (Orchidaceae,Epidendroideae) from Colombia

A new species of the genus Microstylis, M. schneideri is described and illustrated based on Colombian material. The taxonomic affinities of the new species are briefly discussed.     

Dendrobium tamenglongense sp. nov. (Orchidaceae) from Manipur,India

Dendrobium tamenglongense R. Kishor, Y. N. Devi, H. B. Sharma, J. Tongbram & S. P. Vij sp. nov. from Manipur, India is described and illustrated as a new species. The new species differs from D. jaintianum in having larger and glabrous leaves with acute apices, green sepal apices, a 1–3‐flowered inflorescence, smaller and non‐fragrant flowers and a 3‐lobed labellum with fimbriate midlobe.     

Bulbophyllum huangshanense sp. nov. (Orchidaceae) from Anhui,China

Bulbophyllum huangshanense, a new species of orchid from Anhui, China, is described and illustrated. This new species is close to B. taeniophyllum with pseudo‐bulbs closely spaced along the rhizome, leathery leaf, entire dorsal sepal, toothed petals, the lateral edges of lateral sepals connate and fleshy lip, but differs from the latter in having roots arising from the node with the pseudo‐bulb, inflorescence much shorter than leaf, flowers pure yellow, lip mobile, and stelidia broadly triangular.     

Myoxanthus oliviae sp. nov. (Pleurothallidinae,Orchidaceae) from Peru

A new species of the orchid genus Myoxanthus, M. oliviae, is described based on Peruvian material. The novelty resembles M. serripetalus from which it differs by the 7–8‐veined lateral sepals (versus 6‐ or 9‐veined), the petals contracted below the apex and expanded again into a sagittate apex (versus apex caudate) and entire lip middle lobe (versus fimbriate). The flowers of M. oliviae are pale brownish‐purple, internally intensively suffused with yellow, dark‐purple spotted. The new species grows among rocks at the elevation of 2700–3100 m a.s.l. A key to Peruvian Myoxanthus representatives is provided.     

Liparis rubescens sp. nov. (Orchidaceae) from Thailand

In the context of an ongoing revision of the orchid genus Liparis in Thailand, we describe and illustrate a new species under the name L. rubescens Tetsana, H. A. Pedersen & Sridith. Morphologically, it is particularly similar to L. dumaguetensis Ames from the Philippines, but it differs in the shape of the lateral sepals and in several characters of the labellum. Among the Liparis species already known from Thailand, L. atrosanguinea Ridl. bears a certain resemblance to the new species, but not so much as to make misidentifications likely. So far, L. rubescens is only known from Khao Nan National Park in the southern Thai province of Nakhon Si Thammarat, but we suggest that it should also be searched for in other parts of peninsular Thailand, southernmost Myanmar and Peninsular Malaysia.     

Campylocentrum guarinae sp. nov. (Vandeae,Orchidaceae) from Colombia

A new species of Campylocentrum from the Colombian Andes, C. guarinae, is described, illustrated and placed within a key to Colombian species of the genus. The new species resembles C. lansbergii from which it differs in vegetative and floral characters. The main differences between these species are described and illustrated.     

Oberonia pygmaea sp. nov. (Orchidaceae) from Thailand

In the context of an ongoing revision of the orchid genus Oberonia in Thailand, we describe and illustrate a new species under the name O. pygmaea Bunpha, H. A. Pedersen & Sridith. Vegetatively, the tiny new species is particularly similar to O. rufilabris Lindl. (widespread in mainland southeast Asia, including Thailand), whereas its floral morphology comes closest to the much larger O. costeriana J. J. Sm. from Sumatra, Java and Sulawesi. So far, O. pygmaea is only known from Pang Ung in the northern Thai province of Mae Hong Son, but we suggest that it should also be searched for in hill evergreen forest in adjoining parts of the Dawna Range, both in Thailand and Myanmar.     

Oberonia swaminathanii sp. nov. (Orchidaceae) from Kerala,India

Oberonia swaminathanii, a new species of Orchidaceae from Wayanad district, Kerala, India is described and illustrated. The new species resembles Oberonia balakrishnanii, O. chandrasekharanii and O. seidenfadeniana by its 3‐lobed labellum and 2‐lobuled midlobe; but differs in having brick‐red coloured flowers, triangular labellum disc, and a subglobose column.     

Oberonia manipurensis sp. nov. (Orchidaceae) from Manipur,India

A new species Oberonia manipurensis Chowlu, Nanda, A. N. Rao, Angela, Bishwajit & Akimpou sp. nov. (Orchidaceae) is described from Manipur, India. It is closely allied to O. pachyphylla King & Pantl. but differs in longer inflorescence, bilaterally flattened to terete leaves, entire bract, subserrate petals and anther cap with obtuse front margin. The species is described in detail and illustrated with a colour plate. The chromosome number for the species is also reported: 2n = 36.     

Schiedeella jean-mulleri sp. nov. and S. esquintlensis sp. nov. (Orchidaceae, Stenorrhynchidinae) from Guatemala

Two new species of the genus Schiedeella Schltr. (Orchidaceae), S. jean-mulleri Szlach., Rutk. & Mytnik and S. esquintlensis Szlach., Rutk. & Mytnik, are described and illustrated. Their taxonomic position is briefly discussed.     

Molecular phylogeny of the neotropical genus Christensonella (Orchidaceae, Maxillariinae): species delimitation and insights into chromosome evolution

Background and Aims

Species'' boundaries applied within Christensonella have varied due to the continuous pattern of variation and mosaic distribution of diagnostic characters. The main goals of this study were to revise the species'' delimitation and propose a more stable classification for this genus. In order to achieve these aims phylogenetic relationships were inferred using DNA sequence data and cytological diversity within Christensonella was examined based on chromosome counts and heterochromatin patterns. The results presented describe sets of diagnostic morphological characters that can be used for species'' identification.

Methods

Phylogenetic studies were based on sequence data of nuclear and plastid regions, analysed using maximum parsimony and maximum likelihood criteria. Cytogenetic observations of mitotic cells were conducted using CMA and DAPI fluorochromes.

Key Results

Six of 21 currently accepted species were recovered. The results also support recognition of the ‘C. pumila’ clade as a single species. Molecular phylogenetic relationships within the ‘C. acicularis–C. madida’ and ‘C. ferdinandiana–C. neowiedii’ species'' complexes were not resolved and require further study. Deeper relationships were incongruent between plastid and nuclear trees, but with no strong bootstrap support for either, except for the position of C. vernicosa. Cytogenetic data indicated chromosome numbers of 2n = 36, 38 and 76, and with substantial variation in the presence and location of CMA/DAPI heterochromatin bands.

Conclusions

The recognition of ten species of Christensonella is proposed according to the molecular and cytogenetic patterns observed. In addition, diagnostic morphological characters are presented for each recognized species. Banding patterns and chromosome counts suggest the occurrence of centric fusion/fission events, especially for C. ferdinandiana. The results suggest that 2n = 36 karyotypes evolved from 2n = 38 through descendent dysploidy. Patterns of heterochromatin distribution and other karyotypic data proved to be a valuable source of information to understand evolutionary patterns within Maxillariinae orchids.Key words: Chromosome number, Christensonella, Cymbidieae, cytotaxonomy, fluorochrome staining, Maxillaria, Maxillariinae, molecular phylogenetics, species delimitation     

Hapalorchis neglecta sp. nov. and H. piesikii sp. nov. (Spiranthinae, Orchidaceae) from the Neotropics

Two new species of Hapalorchis Schltr. ( H. neglecta and H. piesikii ) from the Neotropics (Ecuador and Colombia, respectively) are described and illustrated. The taxonomic position of the taxa is briefly discussed.