On the identity of Festuca jubata Lowe (Poaceae) and the description of a new Festuca species in the Azores Islands

The majority of authors consider Festuca jubata Lowe as an endemic species common to Madeira and the Azores. Saint-Yves proposed that F. jubata was an Azorean endemic and described a geovicarious taxon in Madeira: F. filiformis C. Sm. ex Link in Buch ssp. mandonii St.-Yves. We undertook a complete bibliographical revision of the taxonomy, nomenclature, and chorology of F. jubata s.l. , and contrasted it with morphological and anatomical studies performed on samples from the Azores and Madeira. Azorean plants usually identified as F. jubata had a character combination distinct from that of those with a Madeiran provenance. Saint-Yves' proposal of two independent taxa was correct, but he erroneously considered F. jubata as an Azorean endemic because the name F. jubata was based on Madeiran plants. Consequently, F. jubata auct. pl. from the Azores belongs to a new species.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 493–499.     

Species limits and hybridization zones in Icterus cayanensis–chrysocephalus group (Aves: Icteridae)

One of the best examples of differentiation and hybridization among South American passerine birds is exhibited by Icterus cayanensis (Epaulet Oriole) and Icterus chrysocephalus (Moriche Oriole). Icterus chrysocephalus is a monotypic species restricted to northern South America. Icterus cayanensis is a polytypc species that ranges from Suriname and French Guyana to northern Argentina. Five subspecies are recognized to I. cayanensis. Hybrid zones are known between I. cayanensis and I. chrysocephalus as well as between subspecies of I. cayanenis, even though character variation has never been adequately assessed and mapped. Although molecular data support the hypothesis that I. cayanensis and I. chrysocephalus form a monophyletic group, they do not support the species limits currently recognized within this group. We analysed the geographic variation of plumage characters along the range of this group to map the geographic variation of individual plumage characters and identify the populations that have uniform phenotypic character expression and therefore represent genuine phylogenetic species. We also used molecular data to investigate the phylogenetic relationships among these species. Geographic variation of plumage characters, habitat preferences and molecular data identified four species within I. cayanensis–chrysocephalus clade: an Amazonian species group, formed by I. cayanensis and I. chrysocephalus and a Southern species group composed of I. pyrrhopterus and I. tibialis. The Amazonian species are separated by a relatively narrow hybrid zone along the Amazon valley, whereas the Southern species are separated by a hybrid zone that is larger than the ranges of the two species individually. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 583–597.     

Multi-scale assessment of macroinvertebrate richness and composition in Mediterranean-climate rivers

1. Similar constraints in distant, but climatically comparable, regions may be expected to yield biotic assemblages with similar attributes. Environmental factors that constrain communities at smaller scales, however, may be different between climatically similar regions. Thus, patterns observed at large scales may differ from those detected at small scales, and international comparisons should be focussed at multiple scales. 2. Mediterranean‐climate regions (MCRs) are characterized by remarkable seasonal variability in precipitation and temperature. Accordingly, rivers in these regions have seasonal and predictable floods and droughts, and temporary reaches are frequent. Present in six geographical regions of the world, MCRs have similar environmental constraints and are ideal for testing intercontinental similarities between macroinvertebrate communities. 3. We examined aquatic macroinvertebrate taxon richness and composition in MCRs at three scales: regional, reach and macrohabitat. At the regional scale, the Mediterranean Basin had the highest taxon richness at family level, and southwestern Australia the lowest. Taxonomic composition showed c. 85% similarity between the northern hemisphere MCRs of California and the Mediterranean Basin, which were followed in similarity by South Africa. The two Australian MCRs (South west and South) showed a similarity to each other of about 70% whereas the Chilean fauna was the most distinct. 4. At the reach scale, taxon richness was not significantly different between permanent and temporary reaches in any MCR, whereas taxonomic composition was significantly different among northern hemisphere MCRs. At the macrohabitat scale, taxon richness was not significantly different between lotic and lentic macrohabitats within any of the MCRs, but differences in macroinvertebrate communities were found between macrohabitats when considering regions. 5. Our results show that the strength of similarity between distant but climatically similar regions is scale‐dependent, being highest at the macrohabitat scale. Although the similarities in richness and composition at the macrohabitat scale are presumed to be universal, the seasonal predictability of drought in MCRs is expected to result in characteristic macroinvertebrate responses at the reach scale. We suggest, however, that regional evolutionary history and environmental characteristics may override this general pattern of a similar response of MCRs at different scales. The Mediterranean Basin and California, having similar historical and environmental condition, thus appeared as the most similar MCRs at all scales.     

Biological traits of stream macroinvertebrates from a semi-arid catchment: patterns along complex environmental gradients

1. The relationships between biological traits of macroinvertebrates and environmental characteristics were investigated in streams with contrasting physical, chemical or landscape level attributes. We used an ordination technique, RLQ analysis, which links an environmental table (R) with traits table (Q) through an abundance table (L) to investigate the relationship between habitat characteristics and biological traits.
2. A major environmental axis explaining the distribution of species and their distinctive biological features was obtained. This axis included variables of anthropogenic pressure (agricultural and urban uses) and natural variability (climatic and geologic) that are strongly intercorrelated in the study area, with a clear spatial component.
3. The attributes of species from frequently disturbed systems (small size, multivoltinism, diapause, ovoviviparity, etc.) were associated with semi-arid areas whereas traits common in more stable and favourable environments (large body size, semi-voltinism, isolated eggs, etc.) were found in upland forested areas.
4. The natural climatic variation was proposed as a disturbance axis of a theoretical habitat templet (driven by the intense hydrological disturbances typical of semi-arid streams), while anthropogenic pressure (mainly intensive agriculture) and high salinity, a natural consequence of geology, was proposed as an adversity axis. Different life-histories associated with contrasting environmental features were superimposed in this habitat templet.
5. The ecological–evolutionary scenario in which stream macroinvertebrates have evolved and by which their communities are organized, is closely linked to disturbance, environmental harshness and human pressure.     

Development of polymorphic markers for the root pathogen Thielaviopsis basicola using ISSR‐PCR

Thielaviopsis basicola is a soil‐borne fungal pathogen affecting many important agricultural crops. Little is known regarding the population biology or origin of this pathogen. Polymorphic markers developed for Ceratocystis fimbriata, a species complex phylogenetically closely related to T. basicola, were tested and found not to be useful for T. basicola. In this study 14 primer pairs, seven of which resulted in the amplification of single polymorphic fragments in T. basicola were developed. These primers will enable further studies on this economically important pathogen, and will result in an enhanced understanding of its population structure in different parts of the world.     

Morphology of fruits, seeds and embryos of Argentinian Capparis L. (Capparaceae)

Embryos, seeds and fruits of four species of Capparis L. (Capparaceae) from Argentina are described in this paper: C. flexuosa (L.) L. sensu lato, C. retusa Griseb., C. speciosa Griseb. and C. tweediana Eichl. Chlorophyllous embryos are found in C. flexuosa and C. retusa , species with thin seed coats, dehiscent siliques, and somewhat fleshy red endocarps. Nonchlorophyllous embryos are found in the berry-fruited C. speciosa and C. tweediana , the former with leathery indehiscent fruit wall, the latter with thin-walled dehiscent berries with massive fleshy pulp. The pulp is permeated by seed coat hairs in C. tweediana . The embryos of C. flexuosa , C. retusa and C. tweediana belong to the 'Axile Division, Foliate Subdivision, and Folded Type' of the classification devised by A. C. Martin in 1946. Some features of the embryo of C. speciosa (which are not considered in Martin's classification), support a new subdivision (Massive) and a new morphological type (Unequal cotyledons), characterized by profound anisocotyly, globose shape of the major cotyledon, presence of suberized cells and an undeveloped radicle. Anatomical studies of embryos and seedlings confirm the anisocotyly.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 145 , 209−218.     

DESCRIPTION OF THE SENSORY CHARACTERISTICS OF SPANISH UNIFLORAL HONEYS BY FREE CHOICE PROFILING

Different Spanish unifloral honeys (eucalyptus, sunflower, rosemary, thyme, lavender, citrus, anise, quercus, and lemon blossom) and one multifloral honey were studied by Free-Choice Profiling (FCP) analysis. Generalized Procrustes Analysis (GPA) applied to the FCP data allowed discrimination between samples and provided information on the attributes responsible for the differences observed. The honeys had significantly different sensory characteristics. Textural attributes were the predominant factor in discriminating between samples, and appearance (color included) was also correlated with GPA dimensions to a lesser extent.     

Reproductive structures and systematics of Buxaceae

Buxaceae belong to a grade of families near the base of eudicots. Flowers of these families are characterized by a variable number and arrangement of floral organs. In this study, the anthetic structure of the gynoecium and androecium of representatives of all genera of Buxaceae were comparatively studied, and observations on the flowering processes and pollination biology were made. Styloceras and Notobuxus were studied in detail for the first time. Various features of the morphological analysis support our earlier molecular phylogenetic study. Shared reproductive characters among Sarcococca , Pachysandra and Styloceras are the occurrence of two (rarely three) carpels, the lack of interstylar nectaries, a micropyle formed by both integuments, attractive stamens in male flowers, and fleshy fruits. In addition, Styloceras and Pachysandra share a secondary partition in the ovary. Notobuxus does not seem to be clearly distinct from Buxus . Both have a similar inflorescence and perianth structure; female flowers have three carpels, interstylar nectaries, micropyles formed by the inner integument, rudimentary arils, and they develop into capsular fruits; in male flowers stamens are sessile and the central pistillode is lacking in some species. Thus, it is questionable to justify a separation of Buxus and Notobuxus at genus level. The results further strongly support the placement of Buxaceae among basal eudicots.  © The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 140 , 193–228.     

Drosophyllum lusitanicum, an endangered West Mediterranean endemic carnivorous plant: threats and its ability to control available resources

Drosophyllum lusitanicum (L.) Link (Droseraceae), Erva pinheira orvalhada, an endangered carnivorous plant, is a local endemic of clearings in pine, cork oak and oak forests or their successional shrublands in the western Iberian Peninsula and Morocco. The conservation status, distribution and population dynamics of this species are only partially known, both for Spanish and Portuguese occurrences. Portuguese distribution data from herbarium and bibliographic sources were collected for this study. Field work on 50 populations was undertaken in order to improve knowledge on their conservation status and possible threats. Natural causes, infrastructure and housing construction are stressed as the most important threats. Germination tests were carried out and the distribution patterns, plant height and the number of flowers were studied in an arbitrarily chosen population. A relatively high light requirement and low competitive ability to gain light are considered factors likely for the microdistribution pattern. Drosophyllum lusitanicum cannot compete for light in habitats with intense competition. Seeds from D. lusitanicum have reduced probability of germination when adult plants are already growing in the area. It is hypothesized that seed germination shows a similar pattern to flowering, viz over a considerable time rather than in a sudden flush. This strategy may be a key factor for the species' survival, representing attempts to take advantage of available resources, preventing intraspecific competition and, finally, preventing sudden total disappearance of a population, resulting from any catastrophic events due to natural causes or to human activity. As a result of this study, some conservation measures are suggested.   © The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 140 , 383–390.     

Phylogenetic relationships within Plantago (Plantaginaceae): evidence from nuclear ribosomal ITS and plastid trnL-F sequence data

A molecular phylogenetic study of Plantago L. (Plantaginaceae) analysed nucleotide variation in the internal transcribed spacers (ITS) of nuclear ribosomal and plastid trnL-F regions. Included are 57 Plantago species, with two Aragoa species as the ingroup and three Veronica species as the outgroup. Phylogenetic analysis using maximum parsimony identified five major clades, corresponding to the taxonomic groups Plantago subgenera Plantago, Coronopus, Psyllium, Littorella and Bougueria . Aragoa is sister to genus Plantago . Plantago subgenus Littorella is sister to the other subgenera of Plantago . The results are in general correlated with a morphological phylogenetic study and iridoid glucoside patterns, but Plantago subgenus Albicans is paraphyletic and should be included in Plantago subgenus Psyllium sensu lato to obtain a monophyletic clade with six sections. Plantago section Hymenopsyllium is more closely related to section Gnaphaloides than to section Albicans . Plantago subgenus Bougueria is sister to subgenus Psyllium s.l. section Coronopus in Plantago subgenus Coronopus is subdivided in two series. Only some of the sections can be resolved into series. DNA variation within genus Plantago is high, a result that would not have been predicted on the basis of morphology, which is relatively stereotyped. If we calibrate a molecular clock based on the divergence of P. stauntoni , endemic to New Amsterdam in the southern Indian Ocean, we calculate the time of the split between Plantago and Aragoa to be 7.1 million years ago, which is congruent with the fossil record.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 323–338.