Search

A new species, Corybas papillatus, is described and illustrated from peninsular Thailand. The new species is easily recognized through a combination of the following characters: the purplish flower, the rounded apex of the dorsal sepal, the outer surface of dorsal sepal covered with irregular papillae in the upper half, the lateral sepals adnate laterally at the base to the connate petals, the V-shaped throat, the labellum bearing short hairs, dentate to erose labellum margins, and well-developed conical spurs. A key to the species of Corybas in Thailand is presented.

Paraboea khaoyaica Kaitongsuk, Triboun & Sungkaew, a new species from Southeastern Thailand, is described and illustrated and its conservation status is assessed. The species is currently only known from the type locality.

It is vital to measure the levels of genetic diversity and differentiation between populations in a species to understand the current genetic structure and evolution of the species. Here, MIG-seq (multiplexed inter-simple sequence repeat genotyping by sequencing) was employed to assess the genetic variation in two tropical leguminous tree species, Dalbergia cochinchinensis and D. nigrescens, in Cambodia and Thailand. Sequence data for 255-618 loci, each with an approximate length of 100 bp, were obtained, and the nucleotide diversity, Tajima's D and FST were computed. The estimates calculated from the data obtained by MIG-seq were compared to those obtained by Sanger sequencing of nine nuclear coding genes in D. cochinchinensis in our previous study. The nucleotide diversity at the MIG-seq loci was slightly higher than that at silent sites in the coding loci, whereas the FST values at the MIG-seq loci were generally lower than those at the coding loci, although the differences were not significant. Moreover, nucleotide diversities within populations of the two species were similar to each other, at approximately 0.005. Three and four population clusters were genetically recognized in D. cochinchinensis and D. nigrescens, respectively. Although the populations were differentiated from each other, the levels of differentiation among them, as measured by FST, were higher in D. cochinchinensis than in D. nigrescens. This indicates higher levels of gene flow between the populations in the latter species. We recommend using MIG-seq for quick surveys of genetic variation because it is cost-effective and results in smaller variance in the estimates of population genetic parameters.

Torenia maculata, is a newly recorded species for Thailand. A description, illustrations and comments on its ecology and distribution are provided.

A taxonomic account of the genus Thyrsostachys for Thailand, where its two recognized species, T. oliveri and T. siamensis, are among the most economically important and widely planted native bamboos, is provided. A second-step lectotypification of the name Thyrsostachys oliveri is proposed and information on the natural distribution of the genus is also included.

Six pteridophyte species of five families and 12 spermatophyte species of 10 families are reported from Bolaven Plateau, southern Laos, as new records to the flora of Laos. Moreover, two new species, Sterculia bolavenensis (Malvaceae) and Wikstroemia bolavenensis (Thymelaeaceae), are described. For each species, voucher specimens are cited, photographs are shown and additional information including geographical distribution, ecology and taxonomic notes are provided.

Begonia sirindhorniana, a new species from South-Western Thailand is described and illustrated.

A new species, Sonerila bolavenensis (Melastomataceae), from the Bolaven Plateau, southern Laos, is described and illustrated. Sonerila bolavenensis is easily recognized by its tiny stature up to 3 cm tall (including inflorescence), small ovate to rounded leaves 0.3–1.4 × 0.35–1 cm, petioles 0.2–0.8 cm long, and 1-flowered inflorescence. A vernacular name and preliminary conservation status are provided.

Thunbergia amphaii, a new species from North-Eastern Thailand is described and illustrated. The pseudo-umbel inflorescence is diagnostic for this species. The pollen morphology, especially the size and the pericolpate aperture arrangement, further support this species as new to science.

Mallotus tokiae (Euphorbiaceae), a poorly known species, was described based upon a single fruiting specimen from Surat Thani Province, peninsular Thailand. We found this species with staminate and slightly mature pistillate flowers in Lampi Island, Myanmar. A new locality record, description of flowers, preliminary conservation assessment and DNA barcoding of this species are provided.

Diospyros phuwuaensis, a new species from Phu Wua Wildlife Sanctuary, North-Eastern Thailand is described and illustrated. Photographs, ecological information and an IUCN conservation status are provided. The distinctive morphological characters of the new species and its related species are discussed. Based on cpDNA data, the new species is confirmed as an independent lineage and placed in the Diospyros clade V sensu Duangjai et al. (2009). It has phylogenetic affinities with Diospyros mollis, and then D. fulvopilosa and D. kurzii. Our result supports the assignment of the new species to Diospyros section Kurzella. A revised description and a key to the species of Diospyros section Kurzella is presented.

Diospyros dussaudii is a poorly known species and previous descriptions lacked details about its female flowers and fruits. The species had not been recorded since type collections were made in 1913. As a result of our Diospyros research in Thailand, new specimens and data are now available for this species. In this study, we provide an updated morphological description, illustrations, lectotypification and a distribution map. The species was previously reported to be endemic to Laos; as such, the occurrences in Thailand greatly expand the distribution of the species. In addition, we analysed the phylogenetic relationships between D. dussaudii and other Diospyros species from Southeast Asia and other regions, using DNA sequence data from eight plastid regions. Our phylogenetic analyses indicate that D. dussaudii is closely related to D. castanea, D. dasyphylla and D. insidiosa. Their taxonomic affinities are discussed.

Diospyrosdussaudii is a poorly known species and previous descriptions lacked details about its female flowers and fruits. The species had not been recorded since type collections were made in 1913. As a result of our Diospyros research in Thailand, new specimens and data are now available for this species. In this study, we provide an updated morphological description, illustrations, lectotypification and a distribution map. The species was previously reported to be endemic to Laos; as such, the occurrences in Thailand greatly expand the distribution of the species. In addition, we analysed the phylogenetic relationships between D.dussaudii and other Diospyros species from Southeast Asia and other regions, using DNA sequence data from eight plastid regions. Our phylogenetic analyses indicate that D.dussaudii is closely related to D.castanea, D.dasyphylla and D.insidiosa. Their taxonomic affinities are discussed.

Staurogyne beddomei, a species known previously only from Myanmar, is newly recorded for Thailand. A description, photographs and conservation status are provided - the species is considered to be of Least Concern.

A previously unrecognized species represented by six spirit samples in the collection of the late Gunnar Seidenfaden, pioneering Danish explorer of the Thai orchid flora, is newly described. It is evident that Seidenfaden was perplexed by the material, as three different species names can be observed on the labels (often accompanied by question marks or indications such as “probably”): D. fimbriatum, D. gibsonii and D. chryseum. In our view, the new species has the strongest morphological resemblance to D. fimbriatum, but it differs in characters of the stems, leaves, lateral sepals, petals and labellum. We describe the new species as D. perplexum, the epithet referring to the previously perplexing properties of the material. So far, D. perplexum is only known from NE Thailand, but as the confirmed Thai localities are close to the Laotian border, future finds in Laos might be expected.

A synopsis of the genera Coleus Lour, Equilabium A.J.Paton, Mwany. & Culham and Plectranthus L’Hér. (Lamiaceae, Tribe Ocimeae, Subtribe Plecranthinae) is presented. Generic delimitation follows a recently published molecular phylogeny which identified Coleus as the sister of the remaining genera of Subtribe Plectranthinae; Plectranthus as sister to Tetradenia Benth. and Thorncroftia N.E.Br., and a separate phylogenetically distinct genus Equilabium comprising species previously placed in Plectranthus. In this treatment, 294 species of Coleus, 42 of Equilabium, and 72 of Plectranthus are recognized. All but one of the combinations in Equilabium are new as only the genus and type species have been previously published. Two-hundred and twelve names are changed to combinations in Coleus from Plectranthus, Pycnostachys Hook. and Anisochilus Benth.

Thismia submucronata is described and illustrated as a new species from Thailand. The new species is characterized by 1) vermiform roots, 2) inner perianth lobes forming a convex mitre with a mucro together with three foveae at apex, 3) the inner surface of perianth tube possessing an irregularly reticulate surface without transverse bars, 4) the presence of papillate hairs at the annulus surface and the outer surface of stamen filaments, and 5) the stamens positioned almost at apex of annulus. Morphological description, illustrations of the new species and a comparison with the related species are presented.

Chaowasku, T., A. Damthongdee, H. Jongsook, D.T. Ngo, H.T. Le, D.M. Tran & S. Suddee (2018). Enlarging the monotypic Monocarpieae (Annonaceae, Malmeoideae): recognition of a second genus from Vietnam informed by morphology and molecular phylogenetics. Candollea 73: 261–275. In English, English abstract. DOI: http://dx.doi.org/10.15553/c2018v732a11Recent botanical expeditions in central Vietnam yielded an unknown species of Annonaceae that could not be confidently identified to subfamily, tribe, and genus. Preliminary BLAST® searches based on plastid data have suggested that this taxon is genetically closely-related to the following tribes of subfamily Malmeoideae: Malmeeae, Fenerivieae, Maasieae, Phoenicantheae, Dendrokingstonieae, Monocarpieae, and Miliuseae. Using representatives of Piptostigmateae, another tribe of Malmeoideae, as outgroups and including representatives of all other tribes of Malmeoideae, molecular phylogenetic analyses of seven combined plastid markers (rbcL, matK, ndhF, ycf1 exons; trnL intron; trnL-trnF, psbA-trnH intergenic spacers) inferred the enigmatic Vietnamese taxon as belonging to the monotypic tribe Monocarpieae. Detailed morphological comparisons between this taxon and its sister group, Monocarpia Miq., warranted the recognition of a second genus of Monocarpieae to accommodate our unknown taxon: Leoheo Chaowasku with a single species, Leoheo domatiophorus Chaowasku, D.T. Ngo & H.T. Le. The morphology of the new genus agrees well with the diagnostic traits of Monocarpieae, e.g., a percurrent tertiary venation of the leaves, a highly reduced number of carpels per flower, enlarged and lobed stigmas, multiple ovules/seeds per ovary/monocarp, considerably large monocarps with a hardened pericarp when dry, and spiniform ruminations of the endosperm. However, the new genus does not exhibit two characteristic features of Monocarpia: terminal inflorescences and generally distinct intramarginal leaf veins. In addition, the new genus possesses three autapomorphic characters: hairy domatia on the lower leaf surface, longitudinal ridges on the monocarp surface, and subsessile monocarps with a stout stipe. The tribe Monocarpieae is consequently enlarged to include the genus Leoheo. The enlarged Monocarpieae, along with the recently established monotypic tribe Phoenicantheae and two other related tribes, Dendrokingstonieae and Miliuseae, are discussed.Received: November 4, 2017. Accepted: August 30, 2018. First published online: November 23, 2018.

It is vital to measure the levels of genetic diversity and differentiation between populations in a species to understand the current genetic structure and evolution of the species. Here, MIG-seq (multiplexed inter-simple sequence repeat genotyping by sequencing) was employed to assess the genetic variation in two tropical leguminous tree species, Dalbergia cochinchinensis and D. nigrescens, in Cambodia and Thailand. Sequence data for 255-618 loci, each with an approximate length of 100 bp, were obtained, and the nucleotide diversity, Tajima's D and F

A new species of Lauraceae,Cryptocarya kaengkrachanensisM.Z.Zhang, Yahara & Tagane, from Kaeng Krachan National Park, Phetchaburi Province, southwestern Thailand, is described and illustrated. This species is morphologically most similar toC. amygdalinain that its leaves are pinnately veined, leathery, and apparently glabrous (but microscopically hairy) abaxially, twigs are yellowish brown hairy, and fruits are 1.36 to 1.85 times longer than width. However,C. kaengkrachanensisis distinguished fromC. amygdalinain having the leaves of ovate and elliptic (vs. oblong-lanceolate) with leaf aspect ratio (length:width) from 1.38 to 2.28 (vs. 2.46–3.43), and ovoid fruits (vs. ellipsoid) with stalk distinctly swollen (vs. not or only slightly swollen). In addition, phylogenetic trees constructed based on internal transcribed spacer sequences (ITS) and genome-wide SNPs using MIG-seq showed thatC. kaengkrachanensisis not sister toC. amygdalinaand is distinct from all the otherCryptocaryaspecies hitherto recognized in Thailand. Analysis including other species demonstrates thatC. floribundashould be a synonym ofC. amygdalina, but we recognizeC. scortechiniias a distinct species.

The delimitation of cryptic species is necessary to accurately classify and appropriately conserve biodiversity. Integrative analyses can be incisive in detecting and circumscribing cryptic diversi...

The new species Ornithoboea grandiflora D.J. Middleton and new variety Ornithoboea maxwellii var. minutiflora D.J. Middleton are described.

Curcuma prasina (Zingiberaceae), a stenoendemic species from Thailand, is described and illustrated here. It differs from other similar species in Curcuma subgenus Hitcheniopsis in Thailand in its inflorescences composed of fertile green bracts only (lacking any white coma bracts), purple staminodes, and purple labellum with a bright yellow centre extending from the base to about two-thirds of the labellum towards the apex.

Ormosia mekongensis Mattapha, Suddee & Rueangr. is described as a new species and illustrated. Its conservation status is assessed and its distribution is mapped. There other species, Ormosia grandist

Two species of Araliaceae, Heteropanax thaiensis Tagane, Suddee & Rueangr., a new species from Phu Kradueng National Park, Loei Province, and Schefflera wrayi (King) R.Vig., from Khao Luang National Park, Nakhon Si Thammarat, formerly known only from Malaysia, are added to the flora of Thailand. Descriptions and illustrations, as well as DNA barcodes of rbcL and matK are provided based on our newly collected specimens.

A new species of Asplenium (Aspleniaceae), A. minutifolium Kanem. & Tagane, from Phu Kradueng National Park, Loei Province, Northeast Thailand and Khao Yai National Park, Nakhon Nayok Province, Central Thailand, is described and illustrated. This species can be distinguished from all similar species in East and South-East Asia by its simple and small lamina (1–5 × 0.3–0.7 cm), small and entire pinnae (1–4 × 0.8–2.5 mm), reflexed pinna arrangement (>90° from the midrib) in the lower 2/3 of the lamina and a sori arrangement that is almost always arranged in a single row on the basiscopic vein.

Porpax scaposa is lectotypified. This species is endemic to northern Thailand, and was based on Garrett 717 (BKF, K) when published. We here select the Kew sheet, K000913725, as the lectotype.

A synopsis of the genera Coleus Lour, Equilabium A.J.Paton, Mwany. & Culham and Plectranthus L’Hér. (Lamiaceae, Tribe Ocimeae, Subtribe Plecranthinae) is presented. Generic delimitation follows a recently published molecular phylogeny which identified Coleus as the sister of the remaining genera of Subtribe Plectranthinae; Plectranthus as sister to Tetradenia Benth. and Thorncroftia N.E.Br., and a separate phylogenetically distinct genus Equilabium comprising species previously placed in Plectranthus. In this treatment, 294 species of Coleus, 42 of Equilabium, and 72 of Plectranthus are recognized. All but one of the combinations in Equilabium are new as only the genus and type species have been previously published. Two-hundred and twelve names are changed to combinations in Coleus from Plectranthus, Pycnostachys Hook. and Anisochilus Benth.

Nervilia plicata is a morphologically variable terrestrial orchid with a wide geographic range in tropical Asia. Several forms have previously been recognised as distinct taxa due primarily to differences in the size, outline and colour of perianth parts. As a first step towards understanding the links between floral polymorphism, pollination ecology and genetic differentiation within the N. plicata complex, we sought to ascertain whether distinct colour morphs in 18 populations in Thailand and South China were correlated with discrete differentiation in macro- or micromorphological characters. Perianth morphology was studied in the field and under stereomicroscopy, and labellum anatomy was examined using light microscopy and scanning electron microscopy. Phenetic analyses comprising Principal Coordinate Analysis (PCoA) and Unweighted Pair Group Method with Arithmetic Mean (UPGMA) of 16 characters revealed four clusters representing distinct floral morphs — pink morph with small, entire labellum; purple morph with large, undulate labellum; white and yellow morph with large, entire labellum; and white and yellow morph with small, entire labellum — among which the size, shape, density and periclinal wall surface of dome-shaped papillae in the secretory zone of the labellar adaxial epidermis varied discontinuously. Our results provide evidence of micromorphological differentiation among N. plicata populations in parts of tropical Asia. Pollinator observations and analyses of genetic diversity are required to establish whether this variation is of any ecological, evolutionary or taxonomic significance.

The Cirrhopetalum alliance is a loosely circumscribed species-rich group within the mega-diverse genus Bulbophyllum (Orchidaceae). The monophyletic status of the alliance has been challenged by previous studies, although established sectional classifications have yet to be tested in a phylogenetic context. We used maximum likelihood and Bayesian analyses of DNA sequence data (cpDNA: matK and psbA-trnH; nrDNA: ITS and Xdh; 3509 aligned characters; 117 taxa), including all sections putatively associated with the Cirrhopetalum alliance, to reconstruct the phylogeny. We mapped 11 selected categorical floral characters onto the phylogeny to identify synapomorphies and assess potential evolutionary transitions across major clades. Our results unequivocally support the recognition of an amended Cirrhopetalum alliance as a well-supported monophyletic group characterized by clear synapomorphies, following the inclusion of sect. Desmosanthes and the exclusion of five putative Cirrhopetalum-allied sections. Most sections within the Cirrhopetalum alliance are demonstrated to be polyphyletic or paraphyletic, necessitating a new sectional classification. The inclusion of sect. Desmosanthes revolutionizes our understanding of the alliance, with significant evolutionary transitions in floral characters detected. We further investigated six continuously variable characters of the sepals and labellum, and detect phylogenetic conservatism in labellum width and the evolutionary lability of lateral sepal length, which can partly be explained by the different functional roles they play in pollination and pollinator trapping.

Garcinia nuntasaenii Ngerns. & Suddee (Clusiaceae), a new species from north-eastern Thailand, is described and illustrated. It is a dioecious shrub in dry evergreen forest at ca 150–220 m altitude.

In this paper we report various findings from our ongoing studies of Crepidium (Orchidaceae), mainly conducted in preparation of the Flora of Thailand account on the genus: (1) the new combinations C. chamaeorchis (Schltr.) Nuammee, Seelanan, Suddee & H.A. Pedersen and C. szemaoense (Tang & F.T. Wang) Nuammee, Seelanan, Suddee & H.A. Pedersen are made and substantiated; (2) a putative natural hybrid between C. acuminatum (D. Don) Szlach. and C. polyodon (Hook.f.) Szlach. is discussed and highlighted as being the first convincing case of natural hybridization reported for Crepidium ; (3) C. bahanense (Hand.-Mazz.) S.C. Chen & J.J. Wood, C. josephianum (Rchb.f.) Marg., C. maximowiczianum (King & Pantl.) Szlach. and C. micranthum (Hook.f.) Szlach. are reported as new national records for Thailand; (4) the name C. josephianum (Rchb.f.) Marg. is lectotypified. All taxa treated in this paper are documented by photos of live plants from their natural habitat in Thailand, and for each newly recorded species we provide a morphological description based on Thai material.