A phylogenetic hypothesis for tribe Podochileae with emphasis on subtribe Eriinae s.s. is based on nucleotide sequences of the nuclear ITS and four plastid regions (matK, trnL-F spacer, trnL intron and ycf1). The strict consensus tree based on parsimony is largely congruent with the maximum likelihood tree with a few major differences; most importantly, monophyly of Podochileae as recently circumscribed is strongly supported by the maximum likelihood tree but not recovered in the parsimony analysis. Monophyly of Thelasiinae s.s. (without Ridleyella) and Eriinae s.l. (including Podochilinae) is supported, whereas Eria s.l. appears polyphyletic. The generic circumscription of Eriinae s.s. (excluding Podochilinae) is revised, and 21 genera are accepted, including two not previously recognized. Nomenclatural changes and a key to genera in Eriinae are provided.

The delimitation of cryptic species is necessary to accurately classify and appropriately conserve biodiversity. Integrative analyses can be incisive in detecting and circumscribing cryptic diversity, especially in species complexes whose members are delineated by minor or overlapping morphological variation. We adopt an integrative approach to assess species relationships and resolve species boundaries in the taxonomically difficult Nervilia adolphi/punctata species alliance of N. sect. Linervia, an Old World complex of reduced, one-flowered terrestrial orchids that is both species-rich and poorly known in tropical and warm temperate Asia. We sampled 12 of the 27 known species of the alliance in Asia, including all four species reported from Thailand and a further 20 plants collected in that country that could not be satisfactorily identified using morphology alone. Phylogenetic analyses using one nuclear (ITS) and two plastid (matK and trnL-F) markers confirmed both N. sect. Linervia and the alliance itself as monophyletic, and corroborated 11 of the 12 sampled species; N. punctata proved polyphyletic, with the Thai samples referred to this Indonesian species falling sister to the Himalayan N. mackinnonii. The 20 unidentified Thai samples formed three distinct, strongly supported clades. STACEY, a Bayesian coalescence approach to species delimitation, resolved the same three clusters, but provided evidence suggesting that one comprised two distinct sub-clades. Building on this genetic evidence, we identify subtle morphological differences and invoke a diagnosable species concept to circumscribe three previously unrecognized cryptic species from Thailand. This objective approach to species delimitation validates ostensibly minor morphological differences as a basis for differentiating species within the alliance, paving the way for a global analysis of species boundaries throughout the genus as a whole.

Background and aims – Bulbophyllum, the largest genus in Orchidaceae, exhibits a diverse morphology in both reproductive and vegetative characters. While trait diversity and evolution has been extensively studied in Malagasy species and within the Cirrhopetalum alliance clade, the evolution of reproductive and vegetative characters at the whole level of the Asian clade remains largely unexplored. Material and methods – We reconstructed the phylogeny of approximately 11% of all Asian Bulbophyllum species using Bayesian inference and maximum likelihood estimation based on nuclear (ITS) and chloroplast (matK, psbA-trnH) DNA sequence data. This phylogenetic framework allowed us to examine the evolution of two vegetative and four floral characters through ancestral state reconstruction. Key results and conclusion – The ancestral character states of the Asian clade of Bulbophyllum include a single leaf, distinct pseudobulbs, multiple-flowered inflorescences, and lateral and dorsal sepals similar in length. One-leaved pseudobulbs evolved into two-leaved pseudobulbs multiple times. Distinct pseudobulbs gave rise to indistinct pseudobulbs twice. Multiple-flowered inflorescences shifted to solitary flowers and 2–3-flowered inflorescences multiple times, with some instances of evolutionary reversal. Lateral sepal elongation also presents a convergent evolutionary scenario.

Muangsan N, Saensouk P, Chanokkhun T, Watthana S. 2022. Comparative leaf epidermis study in Habenaria spp. (Orchidaceae) from Thailand. Biodiversitas 23: 4159-4168. The variation of epidermal and stomatal characteristics could be used for plant classification, including orchids. This study aimed to investigate leaf epidermis characters of Habenaria from Thailand and focused on the H. rhodocheila group and related species. Fourteen accessions belonging to 10 species were studied and compared. Epidermal peels were taken from the upper and lower surfaces of the leaves and were observed under a light microscope. The stomata of all accessions studied were distributed only in the lower epidermis, where they were hypostomatic and anomocytic. The epidermal cell density showed significant differences between the two surface sides. The stomatal size is significantly different among all samples. The highest stomatal index was presented in H. rostrata and the lowest on H. rhodocheila (red). There is no gap variation of epidermis characteristics in H. rhodocheila and its closely related species. It is indicated that the leaf epidermal characters are the shared characters of the genus Habenaria from Thailand. H. rostrata has tentatively separated from other species based on epidermal anatomical characteristics.

A new species, Maerua koratensis (Capparaceae), only known from a restricted locality in Nakhon Ratchasima Province, eastern Thailand, is here described and illustrated. This is the second species of Maerua to be described from South-East Asia. This new species is distinguished by the simple leaves, petaliferous flowers with distinctly 4-lobed laciniate disc, and cylindrical, torulose to moniliform fruits. Morphological characteristics of M. koratensis and M. juncea subsp. juncea, its most similar, are compared. A key to the Maerua species occurring in mainland South-East Asia is provided.

Aptrootia khaoyaiensis Polyiam & Lücking is described as new to science from dry dipterocarp forest in central Thailand, based on morphological assessment and sequence data of the mitochondrial small subunit (mtSSU). The new species is characterized by a corticolous habit, a corticate thallus, ascomata typically immersed in the thallus, with a brown to blackish ostiolar region, an inspersed hamathecium, and dark brown, muriform ascospores occurring 1–2 per ascus. Phylogenetic analyses support placement of the new species in Aptrootia; it is morphologically close to A. elatior but differs in the smaller ascospores and the inspersed hamathecium.