Floral anatomy and morphology in thePolygalaceae

Floral morphology and anatomy of 15 genera in thePolygalaceae have been studied. The pentamerous origin of the polygalaceous flower is confirmed and shown to apply to all genera in the family. The keel is interpreted as a single petal, and the androecium as of bimeric origin. Vascular structure in the receptacles ofCarpolobia andMonnina subg.Monnina is described in detail, and a compilation of results, focusing on the vascular supply for the androecium and gynoecium, is given for all genera. Based on similarities and differences in vascularization it is concluded that present taxonomy, in particular the tribal system, needs to be reviewed.     

Leaf micromorphology inAgathis and its taxonomic implications

This study surveys the micromorphological surface structure of the leaves of the conifer genusAgathis (Araucariaceae) from throughout the range of the genus (Malaysia to New Zealand and Fiji) as seen with the scanning electron microscope. These data confirm that the vegetative parts ofAgathis are taxonomically highly conservative, but suggest the Melanesian and New Zealand elements to be distinctive from those of the rest of the genus, and from one another. Conclusions are compared with those that have been derived from studies based on other characters.     

Phylogeny of theCyclanthaceae

The affinities ofCyclanthaceae are discussed, and it is concluded that the sister-group to this family is most probablyPandanaceae. A hypothesis of generic relationships inCyclanthaceae, based on cladistic methods, is presented. Bootstrap analysis and Bremer support (decay index) have been used to test the strength of individual clades, and the result is compared with previously made phylogenetic analyses. TheSphaeradenia group (Chorigyne, Stelestylis, Sphaeradenia, andLudovia) is supported as monophyletic and acceptably resolved, while theAsplundia group (remaining genera inCarludovicoideae) may be paraphyletic, with largely uncertain relationships. A formal recognition of these groups is therefore not justified. The probable character evolution inCarludovicoideae is discussed.     

The taxonomic implications of cranial shape variation in Homo erectus

The taxonomic status of Homo erectus sensu lato has been a source of debate since the early 1980s, when a series of publications suggested that the early African fossils may represent a separate species, H. ergaster. To gain further resolution regarding this debate, 3D geometric morphometric data were used to quantify overall shape variation in the cranial vault within H. erectus using a new metric, the sum of squared pairwise Procrustes distances (SSD). Bootstrapping methods were used to compare the H. erectus SSD to a broad range of human and nonhuman primate samples in order to ascertain whether variation in H. erectus most clearly resembles that seen in one or more species. The reference taxa included relevant phylogenetic, ecological, and temporal analogs including humans, apes, and both extant and extinct papionin monkeys. The mean cranial shapes of different temporogeographic subsets of H. erectus fossils were then tested for significance using exact randomization tests and compared to the distances between regional groups of modern humans and subspecies/species of the ape and papionin monkey taxa. To gauge the influence of sexual dimorphism on levels of variation, comparisons were also made between the mean cranial shapes of single-sex samples for the reference taxa. Results indicate that variation in H. erectus is most comparable to single species of papionin monkeys and the genus Pan, which included two species. However, H. erectus encompasses a limited range of variation given its extensive geographic and temporal range, leading to the conclusion that only one species should be recognized. In addition, there are significant differences between the African/Georgian and Asian H. erectus samples, but not between H. ergaster (Georgia+Africa, excluding OH 9 and Daka) and H. erectus sensu stricto. This finding is in line with expectations for intraspecific variation in a long-lived species with a wide, but probably discontinuous, geographic distribution.     

Phylogeny, diversity, and distribution inExostema (Rubiaceae): Implications of morphological and molecular analyses

The neotropical genusExostema comprises 25 species of trees and shrubs, ranging in distribution from Bolivia to Mexico and throughout the West Indies, with most species endemic to the Greater Antilles. Infrageneric relationships and species-level patterns of evolution were investigated in phylogenetic analyses using morphological, molecular, and combined data sets. All data sets resolved three main species groups which correspond to the three sections recognized byMcDowell (1996). However, the analyses of ITS sequence data placed the two South American species basal to the three main clades. Otherwise, the morphological and molecular data are highly compatible, and produce a more robust yet consistent phylogeny in the combined data analysis. Morphological evolution inExostema involves many specializations for xeric habitats, reflecting repeated ecological shifts from moist forest to exposed, seasonally dry environments during the diversification of the genus. Both moth and bee pollination syndromes are found inExostema, and shifts in pollination ecology appear pivotal to the differentiation of the three sections. Biogeographically,Exostema likely originated in South America and migrated via Central America to the Greater Antilles, where the morphological diversification and speciation are most extensive.     

Embryology of JapaneseMitella (Saxifragaceae) and its taxonomic significance

The embryo sac formation, endosperm formation, and embryo development in all species of JapaneseMitella andM. diphylla of North America were studied. Monosporic 8-nucleate embryo sac formation of thePolygonum type was found in all the species. In endosperm formation, the Cellular type was found in all species of sect.Mitellaria, and the Helobial type inM. nuda, M. diphylla, andM. integripetala. The Helobial type inM. integripetala was somewhat aberrant and approximated to the Cellular type. In embryo development, three types were distinguishable in sect.Mitellaria: Type A (most of the species), Type B (M. acerina) and Type C (M. pauciflora andM. furusei var.furusei). Type B is an intermediate type between A and C.Mitella integripetala also shows Type A, and the types ofM. nuda andM. diphylla are similar to Type A, except for the shape of suspensor. From outgroup comparison, Type A is suggested to be primitive and Type C to be most derivative in sect.Mitellaria. The affinity of some species in sect.Mitellaria is discussed from the embryogenic data obtained.     

Phylogeny of Early Cretaceous spatangoids (Echinodermata: Echinoidea) and taxonomic implications

A phylogenetic analysis of 36 species provides a test for the taxonomy and the history of Early Cretaceous spatangoids. Most taxonomic units from genera to suborders are consistent with the proposed phylogenetic framework. We retain Hemiasterina, Micrasterina, Hemiasteridae, Schizasteridae, Hemiaster , Heteraster , Mecaster , and Periaster as original monophyletic groups. However, all of these clades originate without the classical apomorphies normally ascribed to them. We suggest a revision of their diagnoses and of the generic attributions of basal species. Some ill-defined, 'primitive', and paraphyletic taxa are recognised: Toxaster , Epiaster , Palhemiaster , and Toxasteridae. Even if they do not have phylogenetic meaning, they are retained here, pending a more complete revision.     

Phylogeny and taxonomy of rhizobia

Rhizobia are bacteria that form nitrogen-fixing nodules on the roots, or occasionally the shoots, of legumes. There are currently more than a dozen validly named species, but the true number of species is probably orders of magnitude higher. The named species are listed and briefly discussed. Sequences of the small subunit ribosomal RNA (SSU or 16S rRNA) support the well-established subdivision of rhizobia into three genera: Rhizobium, Bradyrhizobium, and Azorhizobium. These all lie within the alpha subdivision of the Proteobacteria, but on quite distinct branches, each of which also includes many bacterial species that are not rhizobia. It has been clear for several years that Rhizobium, on this definition, is still too broad and is polyphyletic: there are many non-rhizobia within this radiation. Recently, therefore, it has been suggested that this genus should be split into four genera, namely Rhizobium (R. leguminosarum, R. tropici, R. etli), Sinorhizobium (S. fredii, S. meliloti, S. teranga, S. saheli), Mesorhizobium (M. loti, M. huakuii, M ciceri, M. tianshanense, M. mediterraneum), and a fourth, unnamed, genus for the current R. galegae. The evidence and pros and cons are reviewed.     

Phylogeny of oligochaetous Clitellata

Clitellata, with more than one third of all annelid species described, is briefly introduced, and an overview of the hypotheses of phylogenetic relationships among the groups traditionally referred to as oligochaetes is given. The presentation is placed in a historical context and describes the trend to move from intuitive, narrative approaches to more formal analyses of character patterns. Monophyly of the earthworms (the megadriles, or Metagynophora sensu Jamieson), or at least a major part of them (Crassiclitellata sensu Jamieson), and paraphyly of the ‘microdrile’ largely aquatic, groups are supported by both morphological and molecular data. Further, DNA sequences as well as spermatozoal ultrastructure corroborate that all leech-like taxa (Hirudinida, Acanthobdellida and Branchiobdellida) constitute a clade derived within ‘Oligochaeta’, closely related to the family Lumbriculidae. Molecular systematic studies also support relationships already identified on the basis of morphological data, e.g., the position of Naididae within Tubificidae, the position of Phreodrilidae close to, but outside, the same family, and the putative sistergroup relationship between the newly discovered Capilloventridae and the rest of Clitellata. A recent study using 18S rDNA suggests that Enchytraeidae is closely related to Metagynophora, and that these two taxa, which contain all terrestrial oligochaetous clitellates, form a clade derived from aquatic ‘microdriles’ This refutes a recent hypothesis proposing that the ancestor of Clitellata was terrestrial. To a great extent, however, the basal resolution of the oligochaetous clitellates remains unclear.     

Chromosome numbers and their taxonomic implications in the genusPoa of Japan

As part of the work leading to a taxonomic revision ofPoa of Japan, chromosome numbers of nearly all indigenous species of JapanesePoa, together with those of some putative interspecific hybrids, were examined. The following chromosome numbers were found:Poa annua, 2n=28;P. crassinervis, 2m=28;P. acroleuca, 2n=28;P. hisauchii, 2n=28;P. nipponica, 2n=28;P. crassinervis, 2n=28;P. acroleuca, 2n=35;P. tuberifera, 2n=28;P. fauriei, 2n=28;P. radula, 2n=42;P. hakusanensis, 2n=70;P. hayachinensis, 2n=42;P. malacantha var.shinanoana, 2n=63≈98;P. yatsugatakensis, 2n=ca. 71≈74, 77;P. sachalinensis, 2n=63, ca. 64, ca. 74;P. matsumurae, 2n=28;P. ogamontana, 2n=42;P. sphondylodes, 2n=28;P. viridula, 2n=42, 49, 56;P. nemoralis, 2n=70;P. glauca, 2n=42, 49, 56;P. eminens, 2n=42. It became clear that information obtained from chromosome counts is quite helpful in clarifying species boundaries in several species aggregates, such as thePoa acroleuca-hisauchii-nipponica aggregate. Results of the examination of morphological features of the voucher specimens in various species aggregates with taxonomic difficulties were reported, and the needs of some amendments for the species delimitation appearing in current floristic manuals were pointed out. A summary of chromosome counts so far made for JapanesePoa was tabulated. ThePoa flora of Japan characteristically lacked diploid plants.     

A new species and three new combinations in Cyphellophora, with a note on the taxonomic affinities of the genus, and its relation to Kumbhamaya and Pseudomicrodochium.

Cyphellophora guyanensis sp. nov., isolated from leaf litter in French Guyana, is described and illustrated. This fungus is characterized by ampulliform to flask-shaped phialides, with a conspicuous, funnel-shaped collarette, and nearly straight to falcate or slightly sigmoid, (2−)3–6 septate conidia. Cyphellophora guyanensis is compared to the other Cyphellophora species, and the latter genus is compared to Kumbhamaya and Pseudomicrodochium. Kumbhamaya indica, P. fusarioides, and P. suttonii are transferred to Cyphellophora. The phylogenetic relationships of Cyphellophora with other genera of ascomycetes and related mitosporic fungi were inferred from the analysis of the partial nuclear ribosomal DNA SSU sequences data. The analysis supports a placement of Cyphellophora in Chaetothyriales, and probably in the Herpotrichiellaceae This revised version was published online in August 2006 with corrections to the Cover Date.     

Chloroplast DNA variation of Panax (Araliaceae) in Nepal and its taxonomic implications

The restriction site and size variation of five PCR amplified fragments of noncoding chloroplast DNA (cpDNA) was examined in material from 13 populations ofPanax from Nepal and China. Fourteen restriction endonucleases produced 81 restriction site and length variations from the large single-copy region of cpDNA, 27 of which are polymorphic. The cpDNA dataset suggests two distinct groups ofPanax from Nepal (clades I and II). Clade I consists of two populations ofP. pseudoginseng subsp.pseudoginseng, and clade II is composed of material referable toP. pseudogingeng subsp.himalaicus (vars.himalaicus, angustifolius, andbipinnatifidus). The three accessions ofP. pseudoginseng subsp.japonicus andP. ginseng studied from China had cpDNA characters that differed from the HimalayanPanax. The highly distinctive cpDNA profile and morphology ofP. pseudoginseng subsp.pseudoginseng sensu Hara (1970) from central Nepal support its status as a separate species, which has an extremely restricted distribution.     

Chromosome numbers and taxonomic implications in the fern genusAzolla (Azollaceae)

Investigation of chromosome numbers of allAzolla species, and for the first time of hybrids, has been undertaken. Removal of wax from the leaf surface proved invaluable in achieving clear cytological preparations and providing unambiguous chromosome numbers. In contrast to previous records, the speciesA. pinnata, A. filiculoides, A. filiculoides var.rubra, A. caroliniana, A. microphylla, andA. mexicana were found to be 2n=44, andA. nilotica to be 2n=52. Several triploids (2n=66) and one tetraploid (2n=88) were identified. No geographical pattern could be observed in the distribution of triploids which probably derive from the function of unreduced gametes. The chromosome number of hybrids occasionally deviates from the diploid chromosome number (2n=44). The small chromosome size limits karyotypic analysis and only differences in overall chromosome size can be observed. Taxonomic implications of chromosome numbers and sizes are discussed.     

Phylogeny inLabiatae s. l., inferred from cpDNA sequences

Sequences ofrbcL andndhF were analysed independently and in combination to resolve phylogenetic relationships inLabiatae s. l. Monophyly ofLabiatae s. l was supported by all three analyses.Congea tomentosa (Symphoremataceae) is nested withinLabiatae s. l. in therbcL analysis, but emerges as the sister group ofLabiatae s. l. in thendhF and combined analyses. Four noteworthy clades ofLabiate s. l. also are supported by all analyses corresponding to subfamiliesNepetoideae, Lamioideae, Pogostemonoideae andScutellarioideae. Monophyly of subfamiliesChloanthoideae andViticoideae is not supported. A clade comprisingTeucrioideae plusAjuga is supported byndhF and the combined analysis.     

Phylogeny and taxonomic revision of plastid-containing euglenophytes based on SSU rDNA sequence comparisons and synapomorphic signatures in the SSU rRNA secondary structure

Sequence comparisons and a revised classification of the Euglenophyceae were based on 92 new SSU rDNA sequences obtained from strains of Euglena, Astasia, Phacus, Trachelomonas, Colacium, Cryptoglena, Lepocinclis, Eutreptia, Eutreptiella and Tetreutreptia. Sequence data also provided molecular signatures for taxa from genus to class level in the SSU rRNA secondary structure, revealed by a novel approach (search for non-homoplasious synapomorphies) and used for taxonomic diagnoses. Photosynthetic euglenoids and secondary heterotrophs formed a clade, designated as Euglenophyceae (emend.) with two orders: Euglenales and Eutreptiales. The mostly marine Eutreptiales (Eutreptia, Eutreptiella; not Distigma) comprised taxa with two or four emergent flagella (the quadriflagellate Tetreutreptia was integrated within Eutreptiella). The Euglenales (freshwater genera with < or = one emergent flagellum) formed nine clades and two individual branches (single strains); however, only two clades were congruent with traditional genera: Trachelomonas (incl. Strombomonas) and Colacium. Euglena was polyphyletic and diverged into four independent clades (intermixed with Astasia, Khawkinea and Lepocinclis) and two individual branches (e.g. E. polymorpha). Phacus was also subdivided into Phacus s. str. and two combined lineages (mixed with Lepocinclis spp. or Cryptoglena). In consequence, Euglena (s. str.), Phacus and other genera were emended and one lineage (mixed Phacus/Lepocinclis-clade) was recognized as the previously neglected genus Monomorphina Mereschkowsky (1877). The sister clade of Phacus s. str. (mixed Euglena/Lepocinclis-clade) was identified as Lepocinclis Perty (emended).     

The pollen morphology ofOdontites (Scrophulariaceae) and its taxonomic significance

The pollen morphology of 29 species ofOdontites and related genera was examined by light and scanning electron microscopy. Three major pollen types differing fundamentally in exine sculpturing were found. In the parasitic tribePedicularieae retipilate sculpturing is the most widespread type representing a plesiomorphic character state from which the two other types are derived. Of these, reticulate sculpturing is confined toOdontites, whereas a complex retirugulate pattern was found only in the monotypic Near East genusBornmuellerantha. Within the retipilate and the reticulate major types eight minor types were distinguished based on the differential correlation of exine surface morphology, size, shape and amb form. The pollen data are generally well correlated with macromorphological features and furnish important taxonomic characters at the genus—as well as at the specieslevel.     

On the characteristics and taxonomic position of symbiotic Chlorella

Three strains of symbiotic Chlorella (NC64A, CE/76, UTEX-130) could be assigned to C. vulgaris by physiological and DNA-hybridization studies and a fourth symbiotic strain, 3N8/13-1, exhibited characteristics intermediate between C. vulgaris and C. sorokiniana. None of the strains contained detectable sporopollenin or was nutritionally fastidious but the capacity for sugar release (usually maltose) may be a characteristic of all symbiotic Chlorella.     

A reassessment of cleistothecia as a taxonomic character

The morphology of sexual fruit bodies has been historically regarded as a key character in fungal taxonomy. In the 1970s the class Plectomycetes was recognized in order to classify the cleistothecial ascomycetes. However, recent analysis of DNA sequencing data concerning the phylogeny of numerous cleistothecial ascomycetes confirmed that the criterion of the production of closed ascomata without a predefined opening and with an irregular arrangement of the asci at the centrum is of little systematic value, as pointed out by different authors on the basis of morphological studies.