“Barcoding” and ISSR data illuminate a problematic infraspecific taxonomy for Chrysanthemoides monilifera (Calenduleae; Asteraceae): Lessons for biocontrol of a noxious weed

Chrysanthemoides monilifera Tourn. ex Medik is a noxious weed in Australia and New Zealand. It is a widespread species in southern Africa, where it shows considerable morphological variation that has resulted in a confusing infraspecific taxonomy. We use DNA sequence data from the nuclear Internal Transcribed Spacer (ITS) region from 78 samples of this species from its indigenous distribution range and 10 samples from Australia and New Zealand to determine the regions of origin of the invasive plants. These data are augmented by a smaller study using ISSR markers. Bayesian Inference analysis was somewhat resolved, with many weakly supported nodes. Clades with support tended to correspond to infraspecific taxonomic entities, and were geographically coherent. In contrast, a neighbour-net analysis was not as well resolved and indicated considerable reticulation. All analyses of ITS data retrieved two major clades corresponding to Western and Eastern distributions, with some overlap. Samples from New Zealand and Australia correspond to the taxon C. monilifera subsp. monilifera, and are resolved as most closely related to samples from the greater Cape Town area. Biological control agent populations for C. monilifera subsp. monilifera should be sourced from this region in order to avoid host plant incompatibility problems.     

A new infrafamilial taxonomic setting for Liliaceae,with a key to genera and tribes

Based on currently available morphological, karyological, and phylogenetic information, a taxonomic setting of Liliaceae is provided. The family is here organized in 6 tribes, for a total of 15 genera and about 900 species. An identification key for tribes and genera is also provided.     

Flow cytometric,chromosomal and morphometric analyses challenge current taxonomic concepts in the Portulaca oleracea complex (Portulacaeae,Caryophyllales)

Portulaca oleracea is a noxious annual weed of worldwide distribution in temperate to tropical climates. Its taxonomy has been treated in contradictory ways in the past. Various microspecies have been described, lumped into a single species by other authors. We re‐examined the importance of seed size and ploidy variation, previously applied as the most important taxonomic characters, for systematic classification based on accessions from Europe, Asia, Africa and South America using flow cytometry, chromosome counting and morphometry. Sixteen microspecies and six transitional forms, covering the ploidy and seed character variation, proposed for the complex, were studied from 178 populations. Portulaca grandiflora was included as a reference species from outside the complex. DNA hyper‐pentaploidy or hexaploidy were inferred for the majority of accessions which exhibited the full range of seed size. It is recommended that the only species of lower ploidy (either diploid based on x = 12 or tetraploid based on x = 12) encountered, P. nicaraguensis, should be separated from the P. oleracea complex as it deviates in base chromosome number and monoploid genome size. The frequency distribution of seed size was continuous and unimodal within the wild taxa of the complex and in pairs of taxa defined by testa sculpture. Seed size of DNA hexaploids was slightly negatively correlated with sample/standard fluorescence intensities. Our results conflict with the current microspecies concept. Possible reasons underlying the discrepancy are discussed and strategies for future systematic research are suggested. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 144–156.     

Intracellular Development of Enterocytozoon, A Unique Microsporidian Found in the Intestine of AIDS Patients

Enterocytozoon was 1st described in 1985, in an AIDS patient with intestinal malabsorption and diarrhea. Since then, additional cases of infection with this organism have been observed, but only in individuals with AIDS and malabsorption. Intestinal tissue biopsies were obtained from a 45-year-old man prior to AIDS diagnosis, again nine months later and then at autopsy two months later. When the biopsies were examined electron microscopically, both sets contained the microsporidian parasite. However, the 2nd intestinal biopsy, when wasting was much more severe, contained infection in almost every small intestinal enterocyte examined. The parasite was actively developing, allowing us to detail its life cycle. The parasite is apansporoblastic, polysporous and has characteristics not previously reported in the Microsporida: (1) an electron lucent inclusion not usually seen in Microsporida is prominent and always present; (2) extremely elongated sausage-shaped nuclei occur in the proliferative phase of parasite development; (3) the polar tube development uniquely involves the production of electron dense discs, yet results in the formation of a typical spore; and (4) polar tube development occurs prior to the final division of the multi-nucleate sporont. On the basis of these characteristics, we are placing this genus in a new family, Enterocytozoonidae, n. fam.     

Taxonomy of some common Amphidinium species

The taxonomic status of several well known species belonging to the genus Amphidinium (Dinophyceae) has been re-examined. Studies in culture and observations on the micro-anatomy of these organisms suggest that the number of species can be reduced to two, A. klebsii and A. carterae. They may be distinguished on the basis of fundamental differences in chloroplast morphology.     

DNA Sequences from Formalin-Fixed Nematodes: Integrating Molecular and Morphological Approaches to Taxonomy

To effectively integrate DNA sequence analysis and classical nematode taxonomy, we must be able to obtain DNA sequences from formalin-fixed specimens. Microdissected sections of nematodes were removed from specimens fixed in formalin, using standard protocols and without destroying morphological features. The fixed sections provided sufficient template for multiple polymerase chain reaction-based DNA sequence analyses.     

Craniofacial ontogeny in centrosaurine dinosaurs (Ornithischia: Geratopsidae): taxonomic and behavioral implications

Centrosaurine ceratopsians are characterized by well developed nasal horncores or bosses, relatively abbreviated supraorbital horncores or bosses, and adorned parietosquamosal frills. Recent study of several paucispecific (low diversity) bonebed assemblages in Alberta and Montana has contributed greatly to our understanding of ontogenetic and taxonomic variation in the skulls of centrosaurines. Relative age determination of centrosaurines is now possible through examination of ontogenetic change in several characters, including the surface bone morphology of specific skeletal elements. The within-group taxonomy of centrosaurines is based almost entirely on characters of the skull roof, relating particularly to horns and frills. Juvenile and sub-adult centrosaurines are characterized by relatively simple, unadorned skulls compared to their adult counterparts. As in numerous living taxa, the cranial ornaments of centrosaurines developed late in ontogeny, as individuals approached or attained adult size. An important implication arising directly from this study is that juvenile and sub-adult centrosaurines are difficult to distinguish taxonomically at the specific level. Two monospecific genera represented only by immature materials, Brachyceratops montanensis and Monoclonius crassus , cannot be defended and should be considered nomina dubia . The late ontogenetic development and diverse taxonomic variation of horn and frill morphologies support the contention diat these structures are best interpreted as reproductive characters employed in mate competition.     

Description of Careproctus guillemi n. sp. (Pisces: Scorpaeniformes) from Weddell Sea

Careproctus guillemi differs from the other Careproctus species in the following combination of characters: pectoral fin rays 22 (11 + 4+7); pectoral girdle with three round radials (1 + 0+ 1 + 1); mouth oblique and maxillary extending beyond posterior edge of eye. Relationships between C. guillemi and C. longipectoralis are provided. The endochondral pectoral girdle of C. longipectoralis is described for the first time.