Blumea chishangensis sp. nov. (Asteraceae: Inuleae) from Taiwan and new insights into the phylogeny of Blumea.

BACKGROUND: Blumea plants are widely distributed in the tropical areas of Asia, Africa, and Australia, especially tropical Asia. Limited studies left the taxonomy and infrageneric phylogeny of Blumea insubstantial. Here, a new species, Blumea chishangensis S. W. Chung, Z. H. Chen, S. H. Liu & W. J. Huang, from Taiwan is described, and an extended phylogeny is reconstructed to provide new perceptions of Blumea evolution. RESULTS: The new species is distinguished from B. hieraciifolia by the following features: leaf blade sparsely pilose or glabrescent (vs. silky villous), the leaves margins regularly remote mucronulate (vs. double serrate or dentate), capitula pedicelled (vs. capitula sessile or subsessile), and leaves basal rosette or sub-basal rosette and a few cauline (vs. mostly cauline). Phylogenetic analysis based on the ITS, trnL-trnF, and trnH-psbA regions places the new species in the subclade II in B. lacera clade and shows a close relationship with B. axillaris and B. oxyodonta. A key to Blumea species in Taiwan and the studied species in the subclade II is provided. Moreover, the evolutionary inferences of B. conspicua, B. linearis, and B. sinuata are first reported here. The paraphyly of B. formosana and B. sinuata are also revealed for the first time. CONCLUSIONS: Both morphological and molecular data support that B. chishangensis is a new species. Our phylogeny highlights the need for further taxonomic and evolutionary studies on Blumea.

Liparisnapoensis (Orchidaceae), a new species from Guangxi, China.

Liparisnapoensis, a new orchid species belonging to section Cestichis from Guangxi, China is described and illustrated. It occurs in the karst limestone forest. The new species is morphologically similar to L.viridiflora and L.somae, but can be readily distinguished by having narrowly oblong-falcate petals; flabellate-quadrate lip distinctly concave at base and emarginate at apex; conspicuously arcuate column with a pair of wedge-shaped wings.

Phylogenetics of subtribe Orchidinae s.l. (Orchidaceae; Orchidoideae) based on seven markers (plastid matK, psaB, rbcL, trnL-F, trnH-psba, and nuclear nrITS, Xdh): implications for generic delimitation.

BACKGROUND: Subtribe Orchidinae (Orchidaceae, Orchidoideae) are a nearly cosmopolitan taxon of terrestrial orchids, comprising about 1800 species in 47 to 60 genera. Although much progress has been made in recent years of phylogenetics of Orchidinae, considerable problems remain to be addressed. Based on molecular phylogenetics, we attempt to illustrate the phylogenetic relationships and discuss generic delimitation within Orchidinae. Seven DNA markers (five plastid and two nuclear), a broad sampling of Orchidinae (400 species in 52 genera) and three methods of phylogenetic analysis (maximum likelihood, maximum parsimony and Bayesian inference) were used. RESULTS: Orchidinae s.l. are monophyletic. Satyrium is sister to the rest of Orchidinae s.l. Brachycorythis and Schizochilus are successive sister to Asian-European Orchidinae s.s. Sirindhornia and Shizhenia are successive sister to clade formed by Tsaiorchis-Hemipilia-Ponerorchis alliance. Stenoglottis is sister to the Habenaria-Herminium-Peristylus alliance. Habenaria, currently the largest genus in Orchidinae, is polyphyletic and split into two distant clades: one Asian-Australian and the other African-American-Asian. Diplomeris is sister to Herminium s.l. plus Asian-Australian Habenaria. CONCLUSIONS: We propose to recognize five genera in the Ponerorchis alliance: Hemipilia, Ponerorchis s.l., Sirindhornia, Shizhenia and Tsaiorchis. Splitting Habenaria into two genera based on morphological characters and geographical distribution may be the least disruptive approach, and it is reasonable to keep Satyrium in Orchidinae.

New insights into the phylogeny of Burasaieae (Menispermaceae) with the recognition of a new genus and emphasis on the southern Taiwanese and mainland Chinese disjunction.

Taiwan is a continental island lying at the boundary between the Eurasian and the Philippine tectonic plates and possesses high biodiversity. Southern Taiwan, viz. Hengchun Peninsula, is notably floristically different from northern Taiwan. The floristic origin and relationships of the Hengchun Peninsula have been rarely investigated in a phylogenetic context. In this study, data from six plastid and nuclear sequences were used to reconstruct phylogenetic relationships within Burasaieae (Menispermaceae), which mainly inhabits tropical rainforests. The tree-based comparisons indicate that the position of Tinospora sensu stricto conflicts significantly between the cpDNA and ITS trees. However, alternative hypothesis tests from the ITS data did not reject the result of the cpDNA data, which suggests that tree-based comparisons might sometimes generate an artificial incongruence, especially when markers with high homoplasy are used. Based on the combined cpDNA and ITS data, we present an inter-generic phylogenetic framework for Burasaieae. Sampled species of Tinospora are placed in three different clades, including Tinospora dentata from southern Taiwan and T. sagittata from mainland China in an unresolved position alongside six lineages of Burasaieae. By integrating lines of evidence from molecular phylogeny, divergence times, and morphology, we recognize the three Tinospora clades as three different genera, including Tinospora sensu stricto, a new genus (Paratinospora) for T. dentata and T. sagittata, and Hyalosepalum resurrected. Tinospora dentata, now endemic to the Hengchun Peninsula, originated from the Late Eocene (ca. 39Ma), greatly predating the formation of Taiwan. Our study suggests that the flora of the Hengchun Peninsula contains some ancient components that might have migrated from mainland China.

Ixeridium calcicola (Compositae), a new limestone endemic from Taiwan, with notes on its atypical basic chromosome number, phylogenetic affinities, and a limestone refugium hypothesis.

A new species Ixeridium calcicola (Compositae) endemic to middle altitude (ca 1,000-2,000 m asl) limestone mountains of eastcentral Taiwan is described based on morphological and chromosome cytological observations and molecular phylogenetic analyses. Ixeridium calcicola resembles Ixeridium transnokoense, endemic to upper montane and alpine ranges (2,600-3,500 m asl) of Taiwan, in the dwarf habit, but differs in the oblong to lanceolate leaf blades (vs. linear to linear-lanceolate), the presence of mucronulate teeth on the leaf margin and petiole (vs. smooth to very sparse), the dark purple lower leaf surface (vs. greenish), the capitulum with 10 to 12 florets (vs. 5 to 7) and 8 to 10 inner phyllaries (vs. 5, rarely to 7). The basic chromosome number in Ixeridium was known as X = 7. However, the new species has a basic chromosome number of X = 8, as recorded also in the closely related Ixeris. Molecular phylogenetic analyses with the expanded sampling of Ixeridium and Ixeris including both type species supported the monophyly of each of the genera and the placement of the new species in Ixeridium. The result of the phylogenetic analyses and detailed observation of the chromosome morphology revealed that X = 8 in Ixeridium calcicola is derived from centric fission in an ancestral karyomorphotype with X = 7 in Ixeridium. Ixeridium calcicola and Ixeridium transnokoense formed a Taiwan endemic lineage and their estimated divergence time was in the middle Pleistocene. Their common ancestral lineage may have experienced altitudinal distribution shifts in response to glacial-interglacial temperature fluctuation, and a lineage which had not retreated to alpine ranges in an interglacial period likely survived in a limestone refugium, where ordinary plant species did not grow, leading to allopatric speciation.

A new phylogenetic analysis sheds new light on the relationships in the Calanthe alliance (Orchidaceae) in China.

The taxonomy of the Calanthe alliance (Epidendroideae, Orchidaceae), consisting of Calanthe, Cephalantheropsis, and Phaius, has been difficult for orchidologists to understand because of the presence of common morphological features. In this study, in addition to morphological and geographical analyses, maximum parsimony and Bayesian inference analyses were performed based on nucleotide sequences of the nuclear internal transcribed spacer and cpDNA genes of 88 taxa representing the major clades of the Calanthe alliance in China. The results indicated that Cephalantheropsis is monophyletic, while both Phaius and Calanthe are polyphyletic. In Phaius, a total of three species, P. flavus, P. columnaris, and P. takeoi, were segregated to form a new genus, Paraphaius. In Calanthe, subgenus Preptanthe and sect. Styloglossum were both categorized as distinct genera from Calanthe. Our results also confirm that Calanthe delavayi and C. calanthoides are members of Calanthe. Previous studies assigned C. delavayi to Phaius and C. calanthoides to Ghiesbrechtia. Five sections, namely, Alpinocalanthe, Puberula, Ghiesbrechtia, Tricarinata, and Calanthe, three of which are new taxa, were recognized in Calanthe. Therefore, we propose that the Calanthe alliance is composed of six genera: Calanthe, Cephalantheropsis, Paraphaius, Phaius, Preptanthe and Styloglossum.

Molecular systematics of Dendrobium (Orchidaceae, Dendrobieae) from mainland Asia based on plastid and nuclear sequences.

Dendrobium is one of the three largest genera and presents some of the most intricate taxonomic problems in the family Orchidaceae. Based on five DNA markers and a broad sampling of Dendrobium and its relatives from mainland Asia (109 species), our results indicate that mainland Asia Dendrobium is divided into eight clades (with two unplaced species) that form polytomies along the spine of the cladogram. Both Dendrobium and Epigeneium are well supported as monophyletic, whereas sect. Dendrobium, sect. Densiflora, sect. Breviflores, sect. Holochrysa, are paraphyletic/polyphyletic. Many ignored phylogenetic relationships, such as the one of major clades formed by D. jenkinsii and D. lindleyi (two members of sect. Densiflora), the Aphyllum group, the Devonianum group, the Catenatum group, the Crepidatum group, and the Dendrobium moniliforme complex are well supported by both molecular and morphological evidence. Based on our data, we propose to broaden sect. Dendrobium to include sect. Stuposa, sect. Breviflores, and sect. Holochrysa and to establish a new section to accommodate D. jenkinsii and D. lindleyi. Our results indicated that it is preferable to use a broad generic concept of Dendrobium and to pursue an improved infrageneric classification at sectional level, taking into account both morphology and current molecular findings.

A new molecular phylogeny and a new genus, Pendulorchis, of the Aerides-Vanda alliance (Orchidaceae: Epidendroideae).

BACKGROUND: The Aerides-Vanda alliance is a complex group in the subtribe Aeridinae (subfamily Epidendroideae, Orchidaceae). Some phylogenetic systems of this alliance have been previously proposed based on molecular and morphological analyses. However, several taxonomic problems within this alliance as well as between it and its allies remain unsolved. METHODOLOGY/PRINCIPAL FINDINGS: We utilized ITS and five plastid DNA regions in this phylogenetic analysis. Consensus trees strongly indicate that the Aerides-Vanda alliance is monophyletic, and the 14 genera of this alliance can be grouped into the following clades with 14 subclades: 1. Aerides, comprising two subclades: Rhynchostylis and Aerides; 2. Ascocentropsis; 3. Papilionanthe; 4. Vanda, comprising five subclades: Neofinetia, Christensonia, Seidenfadenia, Ascocentrum, and Vanda-Trudelia, in which Vanda and Trudelia form a subclade; 5. Tsiorchis, comprising three subclades: Chenorchis, Tsiorchis, and two species of Ascocentrum; 6. Paraholcoglossum; and 7. Holcoglossum. Among the 14 genera, only Ascocentrum is triphyletic: two species of the Ascocentrum subclade, an independent subclade Ascocentrum subclade in the Tsiorchis clade; the Ascocentrum subclade in the Vanda clade; and one species in the Holcoglossum clade. The Vanda and Trudelia species belong to the same subclade. The molecular conclusion is consistent with their morphological characteristics. CONCLUSIONS: We elucidate the relationship among the 14 genera of the Aerides-Vanda alliance. Our phylogenetic results reveal that the Aerides-Vanda alliance is monophyletic, but it can be divided into 14 genera. The data prove that Ascocentrum is triphyletic. Plants with elongate-terete leaves and small flowers should be treated as a new genus, Pendulorchis. Saccolabium himalaicum (Ascocentrum himalaicum) should be transferred to Pendulorchis. Ascocentrum pumilum, endemic to Taiwan, should be transferred to Holcoglossum. A new combination, Holcoglossum pumilum, was also established. Trudelia should not be recognized as an independent genus. Two new species, Pendulorchis gaoligongensis and Holcoglossum singchianum, were described as well.

Molecular phylogeny of Cypripedium (Orchidaceae: Cypripedioideae) inferred from multiple nuclear and chloroplast regions.

A molecular analysis was performed on 56 taxa in the orchid genus Cypripedium using nrDNA ITS and five chloroplast regions (trnH-psbA, atpI-atpH, trnS-trnfM, trnL-F spacer, and the trnL intron). The genus Cypripedium was confirmed as monophyletic. Our data provided strong support for monophyletic grouping of eight infrageneric sections (Subtropica, Obtusipetala, Trigonopedia, Sinopedilum, Bifolia, Flabelinervia, Arietinum, and Cypripedium) defined in earlier taxonomic treatments, and paraphyletic grouping of two sections (Irapeana and Retinervi). Within the genus Cypripedium, the first divergent lineage consisted of two Mesomaerican species, and subsequently the Cypripedium debile lineage from eastern Asia was split. Our study did not support the notion that two Asian species (Cypripedium subtropicum and Cypripedium singchii) were closely related to either Mesoamerican Cypripedium irapeanum or North American Cypripedium californicum, as indicated by previous interpretations based on morphological evidences. In addition, one pair of vicariant species, Cypripedium plectrochilum (eastern Asia) and Cypripedium arietinum (North America), unique to section Arietinum, was confirmed. Furthermore, within the monophyletic section Cypripedium two previously recognized subsections, Cypripedium and Macrantha, were shown to be paraphyletic. Our results suggested that this section split into two groups based on distribution (North America vs. Eurasia) instead of such previously used, morphological traits as flower color, and the shape of the lips (labellum) and lateral petals.

Phylogenetic systematics of the monotypic genus Hayataella (Rubiaceae) endemic to Taiwan.

Hayataella (Rubiaceae) is a monotypic genus endemic to Taiwan that comprises H. michelloides. In recent years, Hayataella was considered to be synonymous with Ophiorrhiza; however, no specific data have been reported, and the systematic treatment of Hayataella has been unclear. To elucidate the systematic treatment of Hayataella, molecular phylogenetic analyses based on ITS of nrDNA, atpB-rbcL, and trnK/matK of cpDNA were conducted with four Ophiorrhiza species. In the Bayesian and the most parsimonious trees, H. michelloides was included in the Ophiorrhiza clade. The monotypic status of Hayataella is, therefore, not considered appropriate, and the combination Ophiorrhiza michelloides (Masam.) H. S. Lo is supported.