Based on new collections of Machilus from three locations in Cambodia, six species including four new species are recognized: Machilus angustifolia sp. nov., M. bokorensis Yahara & Tagane, M. brevipaniculata Yahara & Tagane, M. cambodiana sp. nov., M. elephanti sp. nov., and M. seimensis sp. nov. Those species are characterized by DNA sequences of rbcL, matK and ITS and vegetative traits of leaves, young twigs and terminal buds. Among four species collected from the same locality, M. angustifolia and M. brevipaniculata have naked terminal buds, but are distinguished by leaf shape and are not close in the ITS tree; M. bokorensis and M. elephanti have scaly terminal buds but are distinguished by the size and morphology of their terminal buds and are not clustered together in the ITS tree. Two additional species differ in their terminal buds, naked in M. cambodiana and scaly in M. seimensis, and are not clustered together in the ITS tree. Four new species are described by comparison with related species and their conservation status is qualified. A new name M. kerrii comb. nov., based on Phoebe kerrii Gamble, is made.

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Dioscorea (Dioscoreaceae) is a diverse genus of more than 600 species. To understand relationships and character evolution within the genus, 273 samples from 183 species (including 28 newly sequenced species) based on four cpDNA regions were analyzed phylogenetically. The phylogenetic tree obtained comprised eleven well-supported major clades, most of which further consisted of more than two subclades. Comparisons with previously proposed infrageneric taxa (23 to 58 sections and associated ‘genera’) showed that some sections/‘genera’ are monophyletic and others polyphyletic. As in previous studies, ‘D. sect. Stenophora’ was sister to the rest of the genus. The present analyses of character state distribution on the tree confirmed that ‘D. sect. Stenophora’ is characterized by having rhizomes, monosulcate pollen and a diploid chromosome number based on x = 10 (plesiomorphies), whereas the rest of the genus has tubers and bisulcate pollen (apomorphies), but is diverse in regard to chromosome number, stem twining direction, fruit types and seed wing morphology. Based on molecular and morphological evidence, two subgenera, Dioscorea (= ‘D. sect. Stenophora’) and Helmia, are proposed. For subgenus Helmia, a revision of the infrageneric classification, especially for the species in the Old World, is needed.

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Most ‘Sohayaki elements’ have been considered to be relict species that originated from ancestors in eastern to southwestern China during the Tertiary Period. Impatiens hypophylla Makino (Balsaminaceae), an endemic Japanese species, is considered to be a representative Sohayaki element. To assess the evolutionary history of the Sohayaki elements, we determined the phylogenetic position of I. hypophylla and estimated its divergence time as well as its ancestral distribution. Three species of Impatiens (I. hypophylla, I. textorii Miq., and I. ohwadae M. Watan. et Seriz.) in Japan form a clade (hereafter called ‘Japanese Impatiens’), which is sister to I. tienmushanica Y. L. Chen, a species endemic to eastern China. Japanese Impatiens and eastern Chinese species likely diverged approximately 5.68 million years ago (mya) (atpB–rbcL) and 7.37 mya (ITS), followed by further divergence of Japanese Impatiens (I. hypophylla, I. textorii, and I. ohwadae) at approximately 3.96 mya (atpB–rbcL) and 5.27 mya (ITS). An estimation of ancestral distribution using S-DIVA revealed that the common ancestor of Japanese Impatiens and the eastern Chinese species occurred in eastern China and the Japanese islands, with the most recent common ancestor of Japanese Impatiens being in the Japanese islands. As a consequence, the common ancestor of Japanese Impatiens and the eastern Chinese species would have widely expanded their distribution in eastern China and the Japanese islands through the East China Sea region in the Tertiary Period. The ancestral range was probably divided into Chinese and Japanese populations due to a vicariance event between mainland China and the Japanese islands. Thereafter, I. hypophylla and other Japanese Impatiens differentiated in the Japanese islands.

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Based on the few differences in ITS sequences and outer morphological traits between Papaver miyabeanum of the Kuril Islands and P. fauriei (Papaveraceae) of Rishiri Island, Hokkaido, the two species are treated as conspecific. However, because of the stable differences in ITS sequences, a tendency toward smaller dimensions in all morphological features, and the somewhat isolated geographical distribution of P. fauriei, we regard the differences to be recognizable at the subspecific level. We therefore propose the name Papaver fauriei (Fedde) Fedde ex Miyabe et Tatew. subsp. shimshirense (Miyabe et Tatew.) Hideki Takah., comb. & stat. nov. for P. miyabeanum of the Kuril Islands.

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Pursegloveia imbakensis H. Okada, Tsukaya and M. Suleiman (Schismatoglottideae, Araceae), a new species from Imbak Canyon Conservation Area, Sabah, Malaysia, is described and illustrated.

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A new peloric form of Cephalanthera erecta (Thunb.) Blume (Orchidaceae) is reported from Hokkaido, Honshu, and Shikoku, Japan. Cephalanthera erecta f. pelorica Hiros. Hayak. & Suetsugu has an inconspicuous lip and stigmas positioned at the apex of the column. The flowers of C. erecta f. pelorica resemble those of the probable peloric form of C. erecta (i.e., C. erecta var. oblanceolata N. Pearce & P. J. Cribb, C. nanlingensis A. Q. Hu & F. W. Xing) and C. longifolia (L.) Fritsch. f. conformis Suetsugu & Hiros. Hayak. However, C. erecta f. pelorica can be distinguished from C. erecta var. oblanceolata, which has a swollen organ on the abaxial surface of the column apex (vs. no swollen organ); C. nanlingensis, which has two staminodes (vs. five staminodes), and C. longifolia f. conformis, which has elliptic, coriaceous leaves (vs. lanceolate, papyraceous leaves).

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Tricyrtis macropoda var. bulbifera, a new variety from northwestern Kyushu, Japan, is describe. It is characterized by bulbils in the leaf axils, asexually generated offspring and sexual reproduction via seeds. Variety bulbifera resembles var. macropoda in its flowers, but differs in producing many apical and axillary cymose inflorescences in addition to the bulbils.

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Two closely related species, Spiranthes sinensis and S. australis (Orchidaceae), have often been distinguished based on the presence or absence of hairs in their inflorescence and on the stems and ovaries: the stems and ovaries of S. australis are generally pubescent, whereas those of S. sinensis are reported to be glabrous. Although S. australis has not been documented to occur in Taiwan, we found a population of Spiranthes with slightly pubescent stems and ovaries at Tahanshan, southern Taiwan. Because the slightly pubescent plants may represent an undocumented extension of the distribution of S. australis, we attempted to identity the slightly pubescent plants by sequencing the ITS and trnL–F intergenic spacer regions. We also compared the lip and column morphology, which have diagnostic characteristics in Spiranthes, and the molecular and morphological data from S. australis, S. sinensis, their close relative, S. hongkongensis, and the unknown plants. The molecular analysis revealed the slightly pubescent plants to be heterozygous for the ITS sequences from S. australis and S. sinensis or from S. hongkongensis and S. sinensis, whereas the trnL–F intergenic spacer region was identical to that of S. sinensis. While we could not completely exclude the possibility that the unknown plants were hybrids between S. hongkongensis and S. sinensis based on the molecular data, we concluded that they were hybrids between the pubescent S. australis and the glabrous S. sinensis (Taiwan type) based on the lip and column morphology.

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