A phylogenetic analysis of the palm subtribe Oncospermatinae (Arecaceae) based on morphological characters

Subtribe Oncospermatinae (Arecaceae: Arecoideae: Areceae) is a diverse group of spiny Old World palms. The subtribe includesOncosperma, a widespread Asian genus of five species, along with seven monotypic genera, all endemic to the Seychelles and Mascarene Islands of the western Indian Ocean. A phylogenetic analysis was conducted in order to test the monophyly of subtribe Oncospermatinae with respect to other Old World genera of tribe Areceae. A matrix of 38 morphological characters was scored for 29 taxa, including 11 species of the Oncospermatinae. A single most parsimonious tree was found, resolving the subtribe as a polyphyletic group of two distinct clades. One clade containingAcanthophoenix, Deckenia, Oncosperma, andTectiphiala was placed as sister to a large group that includes members of subtribes Archontophoenicinae, Arecinae, Iguanurinae, and Ptychospermatinae. The other clade of Oncospermatinae, including the Seychelles endemic generaNephrosperma, Phoenicophorium, Roscheria, andVerschaffeltia, was resolved as sister to the Madagascar endemic subtribe Masoalinae, and may have arisen in the western Indian Ocean region.     

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 systematic histological analysis of palm fruits VII. The Cyrtostachydinae (Arecaceae)

Fruit specimens representing five taxa of the genusCyrtostachys were examined histologically in order to characterize the pericarp anatomy of the monogeneric subtribe Cyrtostachydinae (tribe Areceae, subfamily Arecoideae), as part of an ongoing survey of the family. The pericarp in this genus can be characterized by a combination of papillate epidermis, heavy layer of tanniniferous/pigmented cells below the epidermis, a system of vascular bundles with thick fibrous sheaths with purely fibrous bundles frequently above and below, absence of brachysclereids, and a very thin sclerified locular epidermis. On the basis of pericarp structure alone, the genus might be most closely related to theGronophyllum alliance of the subtribe Arecinae. This diverges somewhat from the hypothesis of relationship with theAreca group of the Arecinae resulting from two DNA-based phylogenetic studies, and even further from the hypothesis of relationship withIguanura suggested by another DNA-based phylogenetic study.     

A systematic histological study of palm fruits. III. Subtribe Iguanurinae (Arecaceae)

This study represents a preliminary sampling of the pericarp histology of the subtribe Iguanurinae (tribe Areceae, subfamily Arecoideae) of the family Arecaceae. At least one sample from each of the 27 recognized genera was examined and illustrated with a line drawing. This sampling serves to characterize fruit structure in the subtribe as a whole, to illustrate the diversity of pericarp adaptations found in the subtribe, to characterize the monotypic genera, to provide hypotheses about the characterization of the larger genera, and to test existing phylogenetic hypotheses about the Iguanurinae. There are no unique tissues present in the pericarp in this subtribe, but genera can be readily characterized by unique combinations and distributional patterns in common tissues. These patterns, and some prominent evolutionary trends, parallel those in related subtribes of Areceae, such as the Ptychospermatinae and Arecinae. Significant in this subtribe is variation in the distribution of tanniniferous cells, raphide-bearing cells and brachysclereids, in the sculpturing of the seed and the locular epidermis, in the thickness of the locular epidermis, in the thickness of the fibrous vascular bundle sheaths, and especially in the number, orientation and distribution of nonvascular fibrous bundles. One major trend is the formation of systems of separate fibrous bundles and their progressive displacement toward the outer layer of the fruit, where a complex exocarp may form. The diversity of pericarp structure in the Iguanurinae is far greater than in the two subtribes previously studied.     

Molecular phylogenetics of the Espeletia complex (Asteraceae): evidence from nrDNA ITS sequences on the closest relatives of an Andean adaptive radiation

The subtribe Espeletiinae (Asteraceae, Heliantheae) comprises morphologically and ecologically diverse plants endemic to the tropical montane paramos of the Andes of Venezuela, Colombia, and Ecuador. Though the ecophysiology and ecology of this adaptive radiation have been well studied, relationships among taxa in the subtribe and between the subtribe and other taxa in the Heliantheae are poorly known. In this study, sequences from the internal transcribed spacer (ITS) region of nuclear ribosomal DNA are used to test previous hypotheses about the phylogenetic position of the Espeletiinae within the Heliantheae and to determine which taxa are the subtribe's closest relatives. Gene phylogenies based on maximum parsimony analyses reveal that the Espeletiinae clade is nested well within the subtribe Melampodiinae and thus should be considered a monophyletic complex of species, not a separate subtribe. The most parsimonious gene trees suggest that the genus Ichthyothere may be the sister taxon to the Espeletia complex and that the genus Smallanthus and a species of Rumfordia are likely among the complex's other closest living relatives. These data offer preliminary insights into the origins of this adaptive radiation and the broader phylogenetic context in which it occurred.     

GENETIC DIVERGENCE AMONG MEDITERRANEAN AND MACARONESIAN GENERA OF THE SUBTRIBE CHRYSANTHEMINAE (ASTERACEAE)

Genetic variation at 17 isozyme loci was used to assess divergence among the four genera comprising subtribe Chrysantheminae (Anthemideae: Asteraceae). The Macaronesian endemic genus Argyranthemum is supported as monophyletic and is about equally divergent at isozyme loci from the other three genera of the Chrysantheminae, Chrysanthemum, Heteranthemis, and Ismelia. Chrysanthemum is native to the Mediterranean whereas Heteranthemis occurs in southern Iberia and Morocco, and Ismelia is endemic to Morocco. The genera Chrysanthemum and Ismelia have a genetic identity of 0.9283, which is comparable to values often seen for congeneric species and indicates that they should be treated as one genus. The isozyme data indicate that three lines consisting of Argyranthemum, Chrysanthemum-Ismelia, and Heteranthemis radiated rapidly from a common ancestor. Divergence times estimated from isozyme data suggest that the initial radiation of the three lines occurred 2.5–3.0 mya. If this is so, then Argyranthemum or its ancestor arrived in Macaronesia after all the islands except La Palma and El Hierro were formed. The evolutionary history of the subtribe is discussed in relation to the climatic and geological events that took place in the Western Mediterranean between the Tertiary and Quaternary, i.e., the first Northern Hemisphere glaciation and desertification of the Sahara region. The high mean genetic identities between species of Argyranthemum suggest that it might have subsequently undergone a second more recent radiation in the Macaronesian Islands. Also, the high mean identity (0.860) between populations in Chrysanthemum and Ismelia suggest that these continental genera might be in the early stages of secondary speciation.     

Explosive avian radiations and multi-directional dispersal across Wallacea: evidence from the Campephagidae and other Crown Corvida (Aves)

The systematic relationships among avian families within Crown Corvida have been poorly studied so far and as such been of limited use for biogeographic interpretations. The group has its origin in Australia and is thought to have colonized Africa and the New World via Asia beginning some 35 Mya when terranes of Australian origin approached Asian landmasses. Recent detailed tectonic mapping of the origin of land masses in the region around Wallace's line have revealed a particularly complex movement of terranes over the last 20-30 Myr. Thus the biogeographic dispersal pattern of Crown Corvida is a particularly exciting case for linking vicariance and dispersal events with Earth history. Here we examine phylogenetic affinities among 72 taxa covering a broad range of genera in the basal radiations within Crown Corvida with an emphasis on Campephagidae and Pachycephalidae. Bayesian analyses of nuclear DNA sequence data identified the family Campephagidae as monophyletic but the large genus Coracina is not. Within the family Pachycephalidae the genera Pachycephala and Colluricincla are paraphyletic with respect to each other. The resulting phylogeny suggests that patterns of dispersal across Wallace's line are complex and began at least 25 Mya. We find evidence of explosive radiations and multi-directional dispersal within the last 10 Myr, and three independent long distance ocean dispersal events between Wallacea and Africa at 10-15 Mya. Furthermore, the study reveals that in the Campephagidae a complex series of dispersal events rather than vicariance is the most likely explanation for the current biogeographic pattern in the region.     

稀有濒危植物珊瑚菜的染色体特征及其演化地位

首次分析了珊瑚菜（ Ｇｌｅｈｎｉａ ｌｉｔｔｏｒａｌｉｓ） 根尖体细胞染色体组型。其核型公式为２ ｎ ＝ ２２＝ １８Ｍ ＋ ４Ｓｍ （２Ｓａｔ） , 核型不对称性属于２Ａ 型。据此讨论了该属在我国伞形科稀有濒危单型属和当归亚族中的演化地位。     

Phylogenetic relationships of subtribe Ecliptinae (Asteraceae: Heliantheae) based on chloroplast DNA restriction site data

Phylogenetic analysis of chloroplast DNA restriction site data for 76 of the 302 genera of Heliantheae sensu lato using 16 restriction endonucleases reveals that subtribe Ecliptinae is polyphyletic and that its genera are distributed in four different lineages. The ecliptinous genera Squamopappus, Podachaenium, Verbesina, and Tetrachyron (of the Neurolaeninae), along with other members of subtribe Neurolaeninae are the basalmost clades of the paleaceous Heliantheae. The mostly temperate species of subtribe Ecliptinae (exemplified by Balsamorhiza, Borrichia, Chrysogonum, Engelmannia, Silphium, Vigethia, and Wyethia) are strongly nested in a clade with the Mesoamerican monotypic genus Rojasianthe as basal. The genera characterized by marcescent ray corollas traditionally classified in subtribe Zinniinae constitute a strongly supported group sister to Acmella, Spilanthes, and Salmea. The largest clade of ecliptinous genera is the most recently derived group within Heliantheae sampled. This large group of mostly Neotropical lowland genera (variously characterized by their winged cypselae, foliaceous phyllaries, and opposite phyllotaxy and exemplified by Perymenium, Wedelia, and Zexmenia) has been and continues to be the most challenging group from a taxonomic standpoint. The study provides new insights as to their relationships that will have a positive impact in future monographic studies of the group. The genera of the Espeletiinae form a monophyletic clade and are sister to members of the Milleriinae and Melampodiinae. This result is consistent with their traditional taxonomic placement with genera such as Smallanthus with which they share a tendency for functionally staminate disc flowers. The phylogenetically enigmatic genus Montanoa is sister to Melampodium. Members of subtribe Galinsoginae are clustered in two main lineages that correspond to the traditional division of the subtribe based on pappus characteristics. There is no support for the monophyly of subtribe Galinsoginae, and the same results indicate some of its genera are paraphyletic.     

A molecular phylogenetic study of the subtribe Glycininae (Leguminosae) derived from the chloroplast DNA rps16 intron sequences

Phylogenetic relationships among 13 genera of the subtribe Glycininae, two genera of the allied subtribe Diocleinae that were included within Glycininae by Polhill, and two genera of the subtribe Erythrininae as outgroups were inferred from chloroplast DNA rps16 intron sequence variation. Pairwise sequence divergence values ranged from identity between Teramnus mollis and T. micans and between T. flexilis and T. labialis to 7.89% between Pueraria wallichii and Pseudeminia comosa across all accessions. Phylogenies estimated using parsimony and neighbor-joining methods revealed that (1) Glycininae is monophyletic if Pachyrhizus and Calopogonium (both Diocleinae) are included within Glycininae; (2) the genus Teramnus is closely related to Glycine, and Amphicarpaea showed a sister relationship to the clade comprising Teramnus and Glycine; (3) the expanded Glycininae including two genera of Diocleinae is divided into three branches, temporarily named I (comprising the rest of the examined taxa), II (Pueraria wallichii), and III (Mastersia), but their relationships are equivocal; and (4) the genus Pueraria, regarded as a closely related genus to Glycine, is not monophyletic and should be divided into at least four genera (a hypothesis supported previously by Lackey).     

On Genera Endemic to China and Occurring in Xizang Plateau Flora

The Xizang (Tibetan) flora with numerous endemics is of importance in Chinese flora. According to recent statistics there are in Xizang 27 genera of spermatophytes endemic to China, being only 2.25% percent of the total number of genera in the Xizang flora. Four of them are regarded as palaeoendemics (14.81%) and the others as neoendemics (85.19%). These endemic genera, of 30 species and 3 varieties, belong to 17 families, of which, Umbelliferae contains 6 genera, 7 species and 3 varieties; Compositae has 6 genera and 7 species, and Gentianaceae 1 genus and 2 species. All the other families each comprises one genus with a single species. The cosmopolitan families together comprising 14 genera with 15 species have the highest perecentage (52.92%) and the tropical ones (5 families, 5 genera with 5 species) come to the next (29.42%), followed by the temperate ones (3 families, 10 genera with 10 species) (17.66%). It shows that these endemic genera are obviously related to the tropical flora and temperate one in essence. According to the number of species, the genera endemic to China and occurring in Xizang flora may be grouped as fallows. Monotypic endemic ones 14 (51.85%) Ditypic endemic ones 6 (22.22%) Oligotypic endemic ones 4 (14.81%) Small endemic ones 3 (11.11%) The formation of the endemic genera is correlated with the topography, climate and environmental conditions, and they may have resulted from the diversification in geography and climatic influence for a long time. The southeastern part of Xizang Plateau is of very diverse ecological conditions, with the adequate precipitation, which may explain the concentration of these endemic genera in this region. The largest similarity coefficient (38.30%) of the genera endemic to China and occurring in Xizang is with those in Qinghai Plateau, next, with those in Yunnan and in Sichuan provinces (both 27.60%), which shows that these endemic genera are related to the floras of the regions mentioned above. The difference in the horizontal distribution of these endemic genera is obviously between the southern and northern parts of Xizang Plateau. The vertical distribution of the genera is also rather obvious, from 800 m to 5200 m above sea level, but concentrated in the zone of 3000 m to 4500 mm. Therefore their occurrence in Xizang is not only affected by the historical environmental conditions but also controlled by the horizontal and vertical distribution. The origin and evolution of some endemic genera, such as Psammosilene, Parateropyrum, Sphaerotylos, Salweenia, Ajaniopsis, Xizangia, Sinoleontopodium, are discussed in this paper. Parateropyrum, a monotypic palaeotropic endemic, belongs to the tribe Atraphaxideae including Atraphaxis, Calligonum and Pteropyrum. It may be a comparatively advanced group in the tribe, and is closely related to the genus Pteropyrum which is distributed in western Asia. The genus Parapteropyrum has possibly survived as a palaetropic-tertiary relic in this region. Sphaerotylos, a member of the subtribe Sphaerotylinae, the tribe Boehmerieae in the family Urticaceae, is a comparatively primitive genus in the tribe Boehmerieae so far known. As the other subtribes, such as Boehmerinae, Sarconchlamydinae, Orecnidinae and Maoutinae, are distributed in the tropics, rarely in the subtropics, the genus is no doubt a palaetropic -tertiary relic. Sinoleontopodium, belonging to the tribe lnuleae in Compositae, is also related to the genus Leontopodium. It is probable that the genus Sinoleontopodium arised later than the other. We come to the conclusion that the southern part of Xizang Plateau is also one of thecentres of the origin and differentiation of genera endemic to China.     

The floral morphology and ontogeny of some Chinese representatives of orchid subtribe Orchidinae

The flower structure and development of ten species in six genera of the orchid subtribe Orchidinae are described and illustrated by scanning electron micrographs. Particular attention is given to the structure of the gynostemium, which for most species is interpreted from ontogenetic data. All the species studied here share a series of features, e.g. the sequence of tepal and anther initiation, the shape and position of the anther, the presence of auricles and basal bulges, the three-lobed condition of the median carpel apex and the lateral lobes of the median carpel embracing the basal ends of the thecae. However, the form and structure of the three carpel apices are most varied in the later development stages or in the adult flower. The genus Hemipilia shows a series of peculiar characters that are quite different from those of the other genera in Orchidinae. The peculiar structure and development of the viscidia in both Amitostigma and Neottianthe indicate that both of them are different from other genera in Orchidinae. The adult floral morphology shows that the genera Galearis and Chusua are not congeneric with Orchis. The separation of the lateral lobes of the rostellum in most genera studied here as well as in the Brachycorythis group from South Africa suggests that this is the ancestral state in the subtribe Orchidinae. In contrast, the conjoining of lateral lobes in Dactylorhiza and Orchis is suggested as a derived character.     

Phylogeny and molecular evolution of the tribe Harpalini (Coleoptera, Carabidae) inferred from mitochondrial cytochrome-oxidase I

The tribe Harpalini is a group of ground beetles with a world-wide distribution that comprises approximately 2000 species and about 238 genera and subgenera. Hypotheses about the phylogenetic relationships of the subtribes of Harpalini are implicit within the systematic criteria put forward by different authors. A 759 bp fragment of the mitochondrial COI was sequenced in 119 specimens (107 species) of 52 genera and subgenera that represent the main lineages of Harpalines, and 3 species of other tribes used as outgroups. A hierarchical study of sequence divergence (under uncorrected and corrected models) and ts:tv ratio pattern analyses were carried out at different taxonomic levels. A low saturation rate was detected at first and second codon positions, whereas A+T richness causes a low transitions:transversions ratio, which suggests--a priori--a high rate of saturation at the third codon position. A progressive accumulation of sequence divergence and a decreasing ts:tv ratio were found from lower to higher taxonomic levels. MP strict consensus, ML, and minimum evolution distance (under ts+tv and tv only schemes) trees showed similar major clades within the tribe. The subtribe Ditomina is a monophyletic lineage with close affinities to the subtribe Harpalina. Harpalina is a polyphyletic lineage as the genus Daptus is always related to members of the subtribe Stenolophina, and the Selenophorines resulted a polyphyletic group related to the subtribe Anisodactylina. Main lineages proposed by Noonan [Quaest. Entomol. 9 (1973) 266] within the subtribe Anisodactylina have been corroborated in this study. The Australian genus Phorticosomus is not related to Ditomina but to the Australian Notiobioids lineage. Most taxa of the subtribe Stenolophina are always included in the same clade, together with taxa of the subtribe Pelmatellina, which might be considered as a lineage of Stenolophina related to Bradycellus and Dicheirotrichus. The subtribe Amblystomina lacks a well-supported relationship to the other subtribes of Harpalini and could not be consistently related to any of them.     

Molecular evolutionary relationships between partulid land snails of the Pacific

Adaptive radiation of partulid land snails in the tropical Pacific has produced an extraordinary array of distinctive morphological, ecological and behavioural types. Here we use part of the nuclear ribosomal RNA gene cluster to investigate the relationships within and between the three partulid genera, Partula, Samoana and Eua. The genera cluster separately, with Samoana and Partula forming monophyletic groups. With one exception, the molecular data generally support the previous generic classification based on genital morphology, even in species that show a number of characteristics otherwise atypical of the genus. Convergent evolution explains morphological similarities between members of different genera. The phylogeny suggests that Samoana has colonized the Pacific from west to east, originating in the area where Eua, believed to be the most ancient partulid genus, is found. An unexplained anomaly is the reported occurrence of a single species of Samoana in the Mariana Islands of the western Pacific. The genus Partula has a disjunct distribution, encompassing islands both to the east and west of the range occupied by Eua. Partula seems to have spread both eastward and westward after the splitting of the Partula lineage.     

Cymbonotus (Compositae: Arctotideae, Arctotidinae): an endemic Australian genus embedded in a southern African clade

The Compositae (Asteraceae) is the largest flowering plant family if described, accepted taxa are considered. Recent revisions in the taxonomy of the family have resulted in the recognition of ten subfamilies and 35 tribes. The tribe Arctotideae is one of the smallest, with around 200 species; it contains two subtribes and several hard-to-place taxa. Previous work has shown that the subtribe Arctotidinae is well defined and is restricted to southern Africa, except for the Australian genus Cymbonotus . Molecular data from internal transcribed spacer (ITS), ndh F, and trn L-F sequences were used (24 previously published sequences; 47 new sequences) to determine the patterns of relationships within the subtribe. Twenty-three samples from the ingroup, including members of all genera and all three species of Cymbonotus , were included in the analysis, together with two outgroup taxa. Cymbonotus is monophyletic and deeply embedded in the subtribe; Haplocarpha is paraphyletic and basal in position; all other genera are monophyletic; however, Arctotis has over 60 species and only eight were sampled for this study, so additional work may prove otherwise. Arctotis is nested high in the tree and has short branch lengths; this may reflect recent radiation. By contrast, the species of the paraphyletic and basal Haplocarpha have long branches, which may indicate an older radiation and a shared ancestry with the remainder of the subtribe. The presence of Cymbonotus in Australia is most probably the result of long-distance dispersal.  Journal compilation © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 1–8. No claim to original US government works     

Phylogenetics of Eulophiinae (Orchidaceae: Epidendroideae): evolutionary patterns and implications for generic delimitation

Eulophiinae comprise c. 270 species divided into nine genera, with the species‐rich terrestrial genus Eulophia representing 60% of this diversity. Remarkable ecological and morphological variation, and an absence of clear diagnostic characters have led to uncertain generic delimitation in the subtribe. Using a combination of new and previously published DNA sequences, we created a dataset representing 122 taxa and all genera of Eulophiinae and inferred a complete generic‐level phylogeny for the subtribe for the first time. Our sampling focused on analysing Afro‐Madagascan taxa and therefore included representatives of the four mostly epiphytic Madagascan endemic genera, the near Madagascan endemic Oeceoclades and additional sampling of the predominantly African genera Eulophia and Orthochilus. In total, 104 new accessions were collected for this study in Zambia and Madagascar (88 of which represented 36 Eulophia spp. and 12 Oeceoclades spp.). Independent plastid and nuclear phylogenetic trees were inferred using Bayesian and maximum‐likelihood algorithms, which recovered strong support for a monophyletic Eulophiinae, the first‐branching position of the mostly epiphytic Madagascan endemic genera, and increased support for recognition of the terrestrial genera Oeceoclades and Orthochilus. Eulophia, the largest genus in the group, was recovered as polyphyletic, but with implications for its classification and that of Geodorum, that was nested in the main Eulophia clade. Although relationships among several genera were resolved with some confidence, the positions of the South African endemic genus Acrolophia and the epiphytic Madagascan endemic Paralophia require further work. Taxon sampling of Asian Eulophia is a priority for future work on the systematics of this group. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 43–56.     

The Genus Artemisia and its Allies: Phylogeny of the Subtribe Artemisiinae (Asteraceae, Anthemideae) Based on Nucleotide Sequences of Nuclear Ribosomal DNA Internal Transcribed Spacers (ITS)

Abstract: Sequences of the internal transcribed spacers (ITS1 and ITS2) of nuclear ribosomal DNA were analysed for 44 Artemisia species (46 populations) representing all the five classical subgenera and the geographical range of the genus, 11 species from 10 genera closely related to Artemisia, and six outgroup species from five other genera of the Anthemideae. The results definitely support the monophyly of the genus Artemisia in its broadest sense (including some taxa segregated as independent genera, like Oligosporus and Seriphidium ). Eight main clades are established in this molecular phylogeny within Artemisia; they agree in part with the classical subdivision of the genus, but they also suggest that some infrageneric groups must be redefined, especially the subgenus Artemisia. The subgenera Tridentatae and Seriphidium are independent from each other. Some of the satellite genera are clearly placed within Artemisia ( Artemisiastrum, Filifolium, Mausolea, Picrothamnus, Sphaeromeria, Turaniphytum ), whereas some others fall outside the large clade formed by this genus (Brachanthemum, Elachanthemum, Hippolytia, Kaschgaria). Our results, correlated to other data such as pollen morphology, allow us to conclude that the subtribe Artemisiinae as currently defined is a very heterogeneous group. Affinities of the largest genus of the subtribe and tribe, Artemisia, and of other genera of the subtribe to some genera from other subtribes of the Anthemideae strongly suggest that subtribe Artemisiinae needs a deep revision and redefinition. Phylogenetic utility of region trnL-F of the plastid DNA in the genus Artemisia and allies was also evaluated: sequences of the trnL-F region in Artemisia do not provide phylogenetic information.     

A Preliminary Study on the Taxonomy of the Family Magnoliaceae

A new system of classification of Magnoliaceae proposed. This paper deals mainly with taxonomy and phytogeography of the family Magnoliaceae on the basis of external morphology, wood anatomy and palynology. Different authors have had different ideas about the delimitation of genera of this family, their controversy being carried on through more than one hundred years (Table I). Since I have been engaged in the work of the Flora Reipublicae Popularis Sinicae, I have accumulated a considerable amount of information and material and have investigated the living plants at their natural localities, which enable me to find out the evolutionary tendencies and primitive morphological characters of various genera of the family. According to the evolutionary tendencies of the characters and the geographical distribution of this family I propose a new system by dividing it into two subfamilies, Magnolioideae and Liriodendroideae Law (1979), two tribes, Magnolieae and Michelieae Law, four subtribes, Manglietiinae Law, Magnoliinae, Elmerrilliinae Law and Micheliinae, and fifteen genera (Fig. 1 ), a system which is different from those by J. D. Dandy (1964-1974) and the other authors. The recent distribution and possible survival centre of Magnoliaceae. The members of Magnoliaceae are distributed chiefly in temperate and tropical zones of the Northern Hemisphere, ——Southeast Asia and southeast North America, but a few genera and species also occur in the Malay Archipelago and Brazil of the Southern Hemisphere. Forty species of 4 genera occur in America, among which one genus (Dugendiodendron) is endemic to the continent, while about 200 species of 14 genera occur in Southeast Asia, of which 12 genera are endemic. In China there are about 110 species of 11 genera which mostly occur in Guangxi, Guangdong and Yunnan; 58 species and more than 9 genera occur in the mountainous districts of Yunnan. Moreover, one genus (Manglietiastrum Law, 1979) and 19 species are endemic to this region. The family in discussion is much limited to or interruptedly distributed in the mountainous regions of Guangxi, Guangdong and Yunnan. The regions are found to have a great abundance of species, and the members of the relatively primitive taxa are also much more there than in the other regions of the world. The major genera, Manglietia, Magnolia and Michelia, possess 160 out of a total of 240 species in the whole family. Talauma has 40 species, while the other eleven genera each contain only 2 to 7 species, even with one monotypic genus. These three major genera are sufficient for indicating the evolutionary tendency and geographical distribution of Magnoliaceae. It is worthwhile discussing their morphological characters and distributional patterns as follows: The members of Manglietia are all evergreen trees, with flowers terminal, anthers dehiscing introrsely, filaments very short and flat, ovules 4 or more per carpel. This is considered as the most primitive genus in subtribe Manglietiinae. Eighteen out of a total of 35 species of the genus are distributed in the western, southwest to southeast Yunnan. Very primitive species, such as Manglietia hookeri, M. insignis and M. megaphylla, M. grandis, also occur in this region. They are distributed from Yunnan eastwards to Zhejiang and Fujian through central China, south China, with only one species (Manglietia microtricha) of the genus westwards to Xizang. There are several species distributing southwards from northeast India to the Malay Archipelago (Fig. 7). The members of Magnolia are evergreen and deciduous trees or shrubs, with flowers terminal, anthers dehiscing introrsely or laterally, ovules 2 per carpel, stipule adnate to the petiole. The genus Magnolia is the most primitive in the subtribe Magnoliinae and is the largest genus of the family Magnoliaceae. Its deciduous species are distributed from Yunnan north-eastwards to Korea and Japan (Kurile N. 46’) through Central China, North China and westwards to Burma, the eastern Himalayas and northeast India. The evergreen species are distributed from northeast Yunnan (China) to the Malay Archipelago. In China there are 23 species, of which 15 seem to be very primitive, e.g. Magnolia henryi, M. delavayi, M. officinalis and M. rostrata, which occur in Guangxi, Guangdong and Yunnan. The members of Michelia are evergreen trees or shrubs, with flowers axillary, anthers dehiscing laterally or sublaterally, gynoecium stipitate, carpels numerous or few. Michelia is considered to be the most primitive in the subtribe Micheliinae, and is to the second largest genus of the family. About 23 out of a total of 50 species of this genus are very primitive, e.g. Michelia sphaerantha, M. lacei, M. champaca, and M. flavidiflora, which occur in Guangdong, Guangxi and Yunnan (the distributional center of the family under discussion) and extend eastwards to Taiwan of China, southern Japan through central China, southwards to the Malay Archipelago through Indo-China. westwards to Xizang of China, and south-westwards to India and Sri Lanka (Fig. 7). The members of Magnoliaceae are concentrated in Guangxi, Guangdong and Yunnan and radiate from there. The farther away from the centre, the less members we are able to find, but the more advanced they are in morphology. In this old geographical centre there are more primitive species, more endemics and more monotypic genera. Thus it is reasonable to assume that the region of Guangxi, Guangdong and Yunnan, China, is not only the centre of recent distribution, but also the chief survival centreof Magnoliaceae in the world.     

Systematics, molecular genetics and historical zoogeography of the viviparous freshwater gastropod Pseudopotamis (Cerithioidea, Pachychilidae): a relic on the Torres Strait Islands, Australia

Freshwater snails of the genus Pseudopotamis Martens, 1894 exemplify one of the most enigmatic distributional patterns among limnic organisms in Australasia. These viviparous cerithioidean gastropods are endemic to the Torres Strait Islands, located on the Sahul shelf corridor between Australia and New Guinea. The occurrence of the two constituent species is highly restricted: P. supralirata (Smith, 1887) on Prince of Wales Island, and P. semoni Martens, 1894 on Hammond Island. Long recognized erroneously as members of the heterogeneous, polyphyletic and widespread Thiaridae, morphological and molecular data presented here reveal that the taxon has to be placed within Pachychilidae, a family otherwise absent from Australia. Comparison with other South East Asian pachychilids, in particular Brotia H. Adams, 1866, Tylomelania Sarasin & Sarasin, 1897, and Jagora Köhler & Glaubrecht, 2003 suggests that Pseudopotamis is most closely related to taxa endemic to Sulawesi (Celebes), thus occurring disjunctly about 2000 km to the west of the Torres Strait. It is only with the Sulawesi pachychilids that Pseudopotamis shares its peculiar uterine brood pouch. Consequently, all pachychilid taxa east of the much-debated Wallace's line (east of Bali, Borneo and the Philippines) possess this uterine incubatory structure. In this paper the historical background of the discovery, the taxonomic history, and an evaluation of the systematic position of Pseudopotamis is provided, including molecular genetic data (genes of cytochrome c oxidase subunit I and 16S ribosomal DNA). Finally, based on the phylogenetic assignment and the recent distribution, implications for a historical biogeography are discussed utilizing a recently developed model for the palaeogeography in Australasia. According to these available data, we favour early vicariant event(s) over recent dispersal.