A revision of the Early Carnian Trachyceratidae (Ammonoidea) of Northeastern Asia

Major morphological features of the shell are studied, and new trachyceratid genera, Boreotrachyceras gen. nov. with the type species B. omkutchanicum (Bytschkov) and Okhototrachyceras gen. nov. with the type species O. seimkanense (Bytschkov), are established based on material from the Lower Carnian of the Omolon Massif and Northern Okhotsk Region. The first record of the genus Trachyceras in the Boreal Realm allows the correlation of the omkutchanicum Zone of Northeastern Asia with the standard aon Zone.     

A revision of Malesian Austrobuxus (Picrodendraceae/Euphorbiaceae s.l. subfam. Oldfieldioideae)

The Malesian species of the predominantly New Caledonian genus Austrobuxus were revised. Three species are recognized. Austrobuxus nitidus is widespread from south Thailand to Borneo. Characteristic for this species are the very short papillae of the caruncle. The caruncle papillae are much longer in the other two, newly described species. Austrobuxus celebicus sp. nov. is endemic to Sulawesi, where it is found on ultramafic soils, and A. dentatus sp. nov. is an endemic species of western New Guinea. The former is notable for the very small fruits and the latter for the teeth‐like glands along the leaf blade margins, unique within the genus.     

Taxonomic revision and phytogeographic studies in Euphorbia (Euphorbiaceae) in the Khorassan provinces of Iran

This study is focused on the genus Euphorbia L. in a part of northeast Iran, viz. the three Khorassan provinces. Since there are many taxa of Euphorbia in Iran which are used in different industries and have significant effects on human and non‐human life it is important to revise their taxonomy. With about 90 species, following Turkey with 91 species, Iran is the second richest country for Euphorbia in Asia. Of these, 30 species are distributed in the Khorassan provinces. This is the first comprehensive work on the genus in this region. According to ‘Flora Iranica’, there are 17 species of Euphorbia in northeast Iran, while according to our results, there are 30 species of Euphorbia in the Khorassan provinces alone. In addition to various new taxonomic and biogeographic results, a new species, viz. E. chamanbidensis, is described. Euphorbia chamanbidensis is closely related to E. aucheri, but seed micro‐morphological characters differentiate them. Two identification keys to the Euphorbia species of the studied area are provided, one based on macro‐morphological characters and another based on seed micro‐morphological characters. Phytogeographic analysis and distribution maps for all species are also presented.     

Thrips pollination of the dioecious ant plant Macaranga hullettii (Euphorbiaceae) in Southeast Asia

Discussion about thrips (Thysanoptera) as main pollinators has been controversial in the past because thrips do not fit the preconception of an effective pollinator. In this study, we present evidence for thrips pollination in the dioecious pioneer tree genus Macaranga (Euphorbiaceae). Macaranga hullettii is pollinated predominantly by one thrips species, Neoheegeria sp. (Phlaeothripidae, Thysanoptera). As a reward for pollinators, the protective floral bracteoles function as breeding sites for thrips and trichomal nectaries on the adaxial surface of the floral bracteoles provide alimentation. Flowering phenology of both staminate and pistillate trees was highly synchronized within 3-4 wk periods. In contrast to pistillate trees, staminate trees start to breed the thrips inside the developing inflorescences ～2 wk before anthesis. Breeding of Neoheegeria sp. in the laboratory indicates that the thrips development is completed within ～17 d. Thus, staminate trees offer breeding sites for one thrips generation until the onset of pollen presentation. Intraspecific pollen transfer by thrips was proved by pollen loads of thrips taken from receptive pistillate inflorescences of M. hullettii. Bagging experiments of different mesh sizes showed that seed set reached almost the level of open-pollinated flowers when exclusively tiny insects like thrips were able to enter the net bags, but no apomictic seed set occurred when no insect access was given to the flowers.     

A mitochondrial stratigraphy for island southeast Asia

Island Southeast Asia (ISEA) was first colonized by modern humans at least 45,000 years ago, but the extent to which the modern inhabitants trace their ancestry to the first settlers is a matter of debate. It is widely held, in both archaeology and linguistics, that they are largely descended from a second wave of dispersal, proto-Austronesian-speaking agriculturalists who originated in China and spread to Taiwan approximately 5,500 years ago. From there, they are thought to have dispersed into ISEA approximately 4,000 years ago, assimilating the indigenous populations. Here, we demonstrate that mitochondrial DNA diversity in the region is extremely high and includes a large number of indigenous clades. Only a fraction of these date back to the time of first settlement, and the majority appear to mark dispersals in the late-Pleistocene or early-Holocene epoch most likely triggered by postglacial flooding. There are much closer genetic links to Taiwan than to the mainland, but most of these probably predated the mid-Holocene "Out of Taiwan" event as traditionally envisioned. Only approximately 20% at most of modern mitochondrial DNAs in ISEA could be linked to such an event, suggesting that, if an agriculturalist migration did take place, it was demographically minor, at least with regard to the involvement of women.     

A Revision of Chinese Phyllanthus (Euphorbiaceae)

The present paper is the outcome of a taxonomic study of Chinese Phyllanthus plants in our flora. Phyllanthus is one of the largest genera in Euphorbiaceae, and is distributed in whole China except for the northwest, extending from 92° to 124° E and 18° to 41°N. It includes 6 subgenera, 7 sections, 33 species and 4 varieties, of which 1 subgenus and 5 species are described as new, and 1 new name and 9 synonyms are proposed.     

A chloroplast genealogy of myrmecophytic Macaranga species (Euphorbiaceae) in Southeast Asia reveals hybridization, vicariance and long-distance dispersals

Macaranga (Euphorbiaceae) includes about 280 species with a palaeotropic distribution. The genus not only comprises some of the most prominent pioneer tree species in Southeast Asian lowland dipterocarp forests, it also exhibits a substantial radiation of ant-plants (myrmecophytes). Obligate ant-plant mutualisms are formed by about 30 Macaranga species and 13 ant species of the genera Crematogaster or Camponotus. To improve our understanding of the co-evolution of the ants and their host plants, we aim at reconstructing comparative organellar phylogeographies of both partners across their distributional range. Preliminary evidence indicated that chloroplast DNA introgression among closely related Macaranga species might occur. We therefore constructed a comprehensive chloroplast genealogy based on DNA sequence data from the noncoding ccmp2, ccmp6, and atpB-rbcL regions for 144 individuals from 41 Macaranga species, covering all major evolutionary lineages within the three sections that contain myrmecophytes. A total of 88 chloroplast haplotypes were identified, and grouped into a statistical parsimony network that clearly distinguished sections and well-defined subsectional groups. Within these groups, the arrangement of haplotypes followed geographical rather than taxonomical criteria. Thus, up to six chloroplast haplotypes were found within single species, and up to seven species shared a single haplotype. The spatial distribution of the chloroplast types revealed several dispersals between the Malay Peninsula and Borneo, and a deep split between Sabah and the remainder of Borneo. Our large-scale chloroplast genealogy highlights the complex history of migration, hybridization, and speciation in the myrmecophytes of the genus Macaranga. It will serve as a guideline for adequate sampling and data interpretation in phylogeographic studies of individual Macaranga species and species groups.     

A Phylogenetic Study of Tribe Euphorbieae (Euphorbiaceae)

A phylogenetic investigation of a monophyletic lineage of spurge plants, tribe Euphorbieae, was conducted to elucidate evolutionary relationships, to clarify biogeographic patterns, and to reexamine the previous classification of Euphorbieae. Cladistic analyses of the 52 morphological characters of 61 species resulted in 2922 equally most parsimonious trees of 193 steps with a consistency index of 0.34. The strict consensus tree indicates genus Anthostema of subtribe Anthosteminae as a likely sister group to all other members of tribe Euphorbieae. The morphological data support a monophyletic origin of subtribe Euphorbiinae, but the subtribes Anthosteminae and Neoquillauminiinae did not form monophyletic groups. Although the previous taxonomic treatments within tribe Euphorbieae have supported the generic status of Pedilanthus, Monadenium, Synadenium, Chamaesyce, and Elaeophorbia, the results of this analysis do not support generic placement of them based on cladistic principles. Recognition of these groups as genera results in Euphorbia becoming a paraphyletic group. One solution to this problem in Euphorbieae is to divide the largest genus Euphorbia into several monophyletic genera and to keep the generic ranks for previously recognized genera. The distribution of basal endemic genera in Euphorbieae showed African and east Gondwanan affinities and strongly indicated that the ancestor of Euphorbieae originated prior to the breakup of Gondwanaland from an old group in Euphorbiaceae. However, some recent African taxa of Euphorbia should be interpreted by transoceanic dispersal from the New World ancestors.     

A Note on Remarkable Exines in Acalyphoideae (Euphorbiaceae)

As part of an extensive study of pollen of Euphorbiaceae that combines transmission electron microscopy with scanning electron microscopy, distinctive exines are reported and documented for certain Acalyphoideae. Cheilosa and Neoscortechinia, which comprise the tribe Cheiloseae, are the only Acalyphoideae with an echinate tectum, but their apertures and exine structure do not support a relationship to Oldfieldioideae. In Ditaxis, one of the three mesocolpia is much smaller than the other two and the pollen can be easily distinguished from all other Euphorbiaceae. In SEM, the tectum of Pycnocoma appears almost complete, but in TEM the exine consists of irregular, mostly discrete tectal elements that narrow to points (=columellae) at the interface with the threadlike footlayer. The operculate grains of Alchornea and Boquillonia have exines with a poorly differentiated double layer of columellae in the mesocolpium, but nearer the endoaperture the lower tier becomes greatly elongated and appears to rest directly on the endexine. Plukenetia polyadenia has a complete tectum and a thick exine with a predominant infratectum of large, occasionally branched columellae that nearer the tectum are combined with densely spaced granules. Plukenetia penninervia has a reticulate tectum of crenate muri and short, sparse columellae. The pollen diversity in Acalyphoideae suggests that the subfamily, many tribes and even genera may not be monophyletic.     

A new species of Croton (Euphorbiaceae) widespread in Mexico

Croton rzedowskii is described, the type being from San Luis Potosí. The species ranges from San Luis Potosi westward to Zacatecas, thence southeastward to Oaxaca.     

Functional andromonoecy in Euphorbia (Euphorbiaceae)

The occurrence of cyathia containing staminate flowers but lacking a pistillate flower was studied in 17 species of Euphorbia. Male cyathia were found in the majority of species studied (88.2%) giving functional andromonoecy. In the male cyathia, the pistillate flower is generally totally absent, but sometimes a vestigial pistillate flower with a non-functional ovary is present. The proportion of male cyathia varied at both the population and species level. The position of male cyathia within the inflorescence showed a constant pattern among species: the proportion of male cyathia decreased from the first to the last levels of the pleiochasia. In general, perennial species had significantly higher proportions of male cyathia than annual species (mean 20 and 2.3%, respectively). In annual species there was a trend for production of male cyathia only in the first level of the inflorescence, whereas in perennials production up to the fourth level of the inflorescence was usual. Functional andromonoecy is common in Euphorbia and represents a new sex segregation in the genus. The selective forces causing this secondary sex segregation in Euphorbia, such as improved pollination or increased outcrossing, are discussed.     

湖南野桐属一新种

本种近似小果野桐M.microc arpus Pax et Hoffm.,区别在于：叶卵形或长圆状卵形,羽状叶脉,基部楔形,下延,两面密被星状绒毛。     

A new species of Phyllanthus (Euphorbiaceae) from Somalia

Phyllanthus lunifolius sp. nov., a completely prostrate dwarf shrub from limestone rocks in the coastal part of central Somalia, is described and illustrated.     

Unusual plasmodium malariae-like parasites in southeast Asia

During malaria surveys in Myanmar, 2 peculiar forms of Plasmodium malariae-like parasites were found. The morphologies of their early trophozoite stages were distinct from that of the typical P. malariae, resembling instead that of Plasmodium vivax, var. minuta, reported by Emin, and Plasmodium tenue, reported by Stephens, both in 1914. Two polymerase chain reaction (PCR)-based diagnoses, which target the same regions in the small subunit ribosomal RNA (SSUrRNA) genes, indicated that these parasites were new variant forms of P. malariae and that they could be separated into 2 genetic types that correlated with the 2 morphological types. Sequence analysis of the SSUrRNA and the circumsporozoite protein genes revealed that they were distinct both from each other and from other known P. malariae isolates and that the P. tenue-like type was closer to a monkey quartan malaria parasite, Plasmodium brasilianum. These results illustrate that the microscopic appearance of human P. malariae parasites may be more varied than previously assumed and suggest the value of molecular tools in the evaluation of malaria morphological variants.