Eurya

Abstract: During the past three decades, molecular taxonomy has made considerable changes in the systematic delimitations of several families in the order Ericales which were formed earlier based on morphology. For instance, the Pentaphylacaceae s.l. has been treated differently by both modern and traditional taxonomists. Modern molecular taxonomists constituted this family by combining the traditionally defined Pentaphylacaceae s.s. (Pentaphylax), Sladeniaceae s.s. (Sladenia), the subfamily Ternstroemioideae with 11 genera of Theaceae s.l. and the genus Ficalhoa. There are also treatments placing the genus Pentaphylax with Ternstroemioideae in Pentaphylacaceae and Ficalhoa with Sladenia in Sladeniaceae. Because most of these genera are poorly studied, investigations on all aspects are important to understand the phylogeny to settle the issues surrounding the treatment of the 14 genera in this family. In the present study, DNA sequences of nrITS and trnL-F genes from species of 11 genera from these 14 genera were generated and analyzed together with sequences from other closely related members of Ericales. The results suggested existence of four distinct lineages viz., Sladenia, Pentaphylax, and tribes Frezierieae (9 genera) and Ternstroemieae (2 genera). Further, it demonstrated that within the biggest lineage, Frezierieae, the Visnea remained sister to the clades Adinandra+Cleyera, Euryodendron+Symplococarpon, Freziera, and finally, Eurya. Based on the evidence, it can be concluded that Sladeniaceae and Pentaphylacaceae are very close to each other and the proposal of merging them into a mega family Pentaphylacaceae s.l. with four tribes, i.e., Sladenieae, Pentaphylaceae, Ternstroemieae, and Freziereae should be considered seriously.

Abstract: The Kathmandu Valley offers the best archive to study the Late Pleistocene climate in Nepal. The Gokarna Formation, constituting the middle part of the sedimentary sequence of the Kathmandu Valley comprises alternating layers of carbonaceous clay, silt, massive to parallel and large scale cross stratified, fine to coarse grained sands and occasional gravel layers, deposited at fluvio-deltaic and lacustrine environment. The organic rich layers of clay, silt, silty-sand and micaceous fine sand consists of abundant plant macro-fossils (fruit, seed and leaves). Plant macrofossils assemblage from the Gokarna Formation (thickness 28.5 m, Dhapasi section) in the northern part of the valley consists of 56 taxa from 35 families. Depending upon the available plant, seven macrofossil assemblages, DS-I to DS-VII in ascending order were established. The common tree and shrubs discovered from this section were Eurya, Ficus, Carpinus, Quercus, Alnus, Rubus, Pyracantha, Zizyphus, Carpinus, Boehmeria etc. Carex, Scirpus triqueter, Scirpus, Polygonum, Euphorbia, Oxalis, Mosla, Viola etc. were the common herbaceous taxa. The constant occurrence of subtropical and warm temperate taxa including Eurya, Ficus, Pyracantha and Zizyphus indicated that subtropical and warm temperate climate continued during the deposition of those macrofossil assemblages. However change in the constituents of those taxa and occurrence of taxa indicating cooler climatic condition like conifers and Betula may indicate minor fluctuation of climate during the deposition of the Gokarna Formation.

Abstract: Eurya is the largest genus in the Ternstroemiaceae. The 13 Eurya species in Taiwan constitute an important element in various habitats from low to high elevated forests in the island. In an attempt to understand the interspecies relationships and geographical history of these 13 species, we sequenced 123 samples representing 32 Eurya species from Taiwan, the Ryukyus, continental China, and Southeast Asia at the nuclear ITS region. Sixteen species of five other genera of Ternstroemiaceae were also incorporated. Molecular phylogenetic trees show that the Eurya species studied form a monophyletic group, organized into five clades with geographical correlations. All the 17 Eurya species from Taiwan and the Ryukyus studied, except E. loquaiana, together constitute two coherent, but distantly related clades: one clade stands at a basal and isolated position, with four out of its five species endemic to these two regions; they are probably Tertiary elements of northern China or their direct descendants. The other clade is much more advanced and has strong affinity to the Eurya in southeast China, which suggests that the members were probably originated from the Quaternary flora of southeast China. Ecological partitioning is thought to be the major mechanism for the speciation of four Taiwan-endemic species from E. chinensis.