Taxonomic separation of the genera Prosthechea and Encyclia (Laeliinae: Orchidaceae) using leaf and root anatomical features

Despite formal separation based on molecular and morphological evidence, the genera Prosthechea Knowles & Westc. and Encyclia Hook. have not been studied in terms of their vegetative anatomy. In this study we examine 16 Brazilian species of these genera. Additionally, one species of subtribe Laeliinae and another from subtribe Oncidiinae were studied in order to evaluate the taxonomic consistency of the anatomic characters observed. Except for Epidendrum crassifolium Lindl., all species possess a velamen differentiated into epivelamen and endovelamen. Endodermal cells with uniformly thickened walls, calcium oxalate raphides and cells with phi thickenings in the cortical region were observed in all species. Silica bodies, raphides and fibre bundles in the mesophyll were common in leaves of all species studied. By contrast, flavonoid crystals were observed in both roots and leaves of Prosthechea only. Encyclia is characterized by the presence of fibre bundles on the subepidermal layer, and a cuticle, which is clearly thicker than that of Prosthechea . These data strongly support the separation of Prosthechea and Encyclia .  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 143 , 293–303.     

Systematic and comparative anatomy of Cymbidieae (Orchidaceae)

Cymbideae comprise an assemblage of 28 genera nearly all of which are represented in this study. Their anatomy is relatively homogenous with the exception of Govenia , in which roots lack velamen and pseudobulb vascular bundles lack sclerenchyma, conditions that do not obtain in other genera. Marginal fibre bundles in leaves of Grammatophyllum and Porphyroglottis consist of clusters of thicker-walled, narrower, epidermis-facing fibres as well as thinner-walled, wider, mesophyll-facing fibres. This feature also occurs in some species of Maxillaria . Baculate tilosomes appear in the roots of a majority of genera in Cymbidieae, as they do in species of Maxillaria , confirming DNA analyses showing a close relationship between tribes Cymbidieae and Maxillarieae. Govenia is singled out both on anatomical and molecular grounds as being ill-placed in Cymbidieae. Cladistic analysis produces only a few tentative hypotheses of phylogenetic relationships among the 28 genera, showing that anatomical characters are of limited value in assessing affinities within this tribe. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 1–27.     

Consistent and variable leaf anatomical characters in Carex (Cyperaceae)

The anatomy and morphology of leaves in Carex have the potential to be taxonomically useful. However, studies on the variability of leaf characteristics in the genus are sparse. Researchers therefore risk using leaf anatomical characters without the knowledge of whether they are consistent in a species. We examined 22 qualitative and seven quantitative leaf anatomy characters from transverse leaf sections to test their consistency across 11 Carex spp. The characters were clearly described and primarily microscopic. Some characters were found to exhibit high levels of intraspecific variation, whereas other characters exhibited high levels of consistency in a species, including the shape of the leaf section, the density of papillae and the size of epidermal cells. Caution must be applied when choosing leaf anatomy to delimit taxa because of the intraspecific variability found in some characters, but sufficient numbers of invariant characters exist to provide useful taxonomic separation. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 371–384.     

Skeletal morphology and the phylogeny of skuas (Aves: Charadriiformes,Stercorariidae)

The skuas (Aves: Charadriiformes, Stercorariidae) consist of two assemblages. On the basis of size, plumage, and distributional similarities, each of the two assemblages has long been considered monophyletic, and this traditional hypothesis has commonly been manifested in the recognition of two genera, Stercorarius and Catharacta; conversely, more recently collected molecular and ectoparasite evidence yields an alternative hypothesis, in which one member of Stercorarius, Stercorarius pomarinus, is more closely related to the forms in Catharacta than to the other Stercorarius sp. In this study we used skeletal morphology to test the competing hypotheses of skua phylogeny. Cladistic analysis of 141 osteological characters provided strong support for the molecular/ectoparasite hypothesis. However, those skeletal data did not support a sister‐taxon relationship between S. pomarinus and Catharacta skua, as inferred from mitochondrial DNA sequence data; instead, they resolved pomarinus as the sister of a monophyletic Catharacta. Additionally, our skeletal evidence did not support a sister‐group relationship between skuas and auks, as constraining skua/auk monophyly increased the tree length by nearly 5%. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 157 , 612–621.     

Leaf morphology and anatomy of Camellia section Camellia (Theaceae)

The delimitations of species in Camellia section Camellia have been disputed for many years, resulting from uncertain relationships among species. Leaf morphological and anatomical characters for 54 species and three varieties in this section were investigated to reveal the relationships. Principal component analysis and cluster analysis were conducted using the transformed data for quantitative and qualitative characters from leaf morphology and anatomy. Combining the results of statistical analysis with comparative leaf characters of morphology and anatomy, we discussed the taxonomic treatment of section Camellia by Chang compared with that of Ming and we conclude that section Camellia consists of c. 50 species. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 456–476.     

Morphological and molecular description of new species of squat lobster (Crustacea: Decapoda: Galatheidae) from the Solomon and Fiji Islands (South‐West Pacific)

The family Galatheidae is among the most diverse families of anomuran decapod crustaceans, and the South‐West Pacific is a biodiversity hot spot for these squat lobsters. Attempts to clarify the taxonomic and evolutionary relationships of the Galatheidae on the basis of morphological and molecular data have revealed the existence of several cryptic species, differentiated only by subtle morphological characters. Despite these efforts, however, relationships among genera are poorly understood, and the family is in need of a detailed systematic review. In this study, we assess material collected in different surveys conducted in the Solomon Islands, as well as comparative material from the Fiji Islands, by examining both the morphology of the specimens and two mitochondrial markers (cytochrome oxidase subunit I, COI, and 16S rRNA). These two sources of data revealed the existence of eight new species of squat lobster, four of which were ascribed to the genus Munida, two to the genus Paramunida, one to the genus Plesionida, and the last species was ascribed to the genus Agononida. These eight species are described along with phylogenetic relationships at the genus level. Our findings support the taxonomic status of the new species, yet the phylogenetic relationships are not yet fully resolved. Further molecular analysis of a larger data set of species, and more conserved genes, will help clarify the systematics of this group. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156 , 465–493.     

Leaf anatomy of Ficus subsection Urostigma (Moraceae)

Species of Ficus subsection Urostigma show much overlapping variation in vegetative morphology, which often precludes correct identification of the species. The aim of this study was to describe the leaf anatomical characters and their variation and to check their suitability for identification. Included were 41 samples belonging to 25 species of subsection Urostigma, four samples belonging to two species of section Leucogyne and one specimen of Ficus glaberrima subsp. siamensis of subsection Conosycea. Transverse sections of lamina, midrib and petiole and cuticular macerations were used, and the observed anatomical characters are described for each species. On the basis of a limited number of studied samples, leaf anatomy shows little variation within each species and each species has a unique combination of character states, facilitating identification. Ficus arnottiana shows some leaf anatomical characters that are quite different from those of other members of subsection Urostigma, including a multiple epidermis and enlarged lithocysts on both sides of the leaf. Both characters are generally considered as typical for Ficus subsection Conosycea. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 259–281.     

Systematic and comparative anatomy of Maxillarieae (Orchidaceae), sans Oncidiinae

On the basis of floral and vegetative morphology, 63 tropical American genera have been recognized within Maxillarieae. We were able to examine anatomical material of all subtribes, excluding Oncidiinae. Stegmata with conical silica bodies occur in leaves and stems of all subtribes excluding Ornithocephalinae, and pericyclic stegmata found in roots are characteristic of Lycastinae. Lycastinae and Maxillariinae are characterized by foliar glands, foliar fibre bundles and tilosomes. Endodermal cells are U-thickened in most Zygopetalinae; O-thickened in most Lycastinae, Ornithocephalinae and Telipogoninae; variously thickened in Maxillariinae; and thin-walled in Cryptarrhena lunata . Water-storage cells varied from thin-walled to variously banded throughout Maxillarieae. Cladistic analyses using anatomical characters yielded no resolution among subtribes, illustrating that anatomical characters are of limited value in assessing relationships within this tribe.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 251–274.     

Reassessment of the cranial characters of Glossotherium and Paramylodon (Mammalia: Xenarthra: Mylodontidae)

Nomenclatural confusion has existed within the Mylodontinae for several genera, and has resulted in the supposition that Paramylodon of North America is synonymous with Glossotherium of South America. A taxonomic revision of crania for Glossotherium and Paramylodon upholds their separation as distinct genera and provides a list of diagnostic characters that have been lacking. Assessment was made using principal components analysis for suites of cranial and mandibular measurements, evaluation of ratios and measurement distribution, and by examining qualitative characters. Results show the greatest characterization for the skull comes from differences relating to cranial length versus width, whereas the mandible is predominantly distinguished by qualitative characters of the predental spout. Examination of the Pliocene species Glossotherium chapadmalense from South America shows a combination of characters indicative of each genus, but exhibits more with Glossotherium and is tentatively retained under that genus. The mix of characters indicates that G. chapadmalense is the likely ancestor to Paramylodon, although when and where the transition took place is still unclear. During the evolutionary transition, Paramylodon crania emphasized an increase in length of the palate, whereas those of Glossotherium emphasized an increase in cranial width. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 885–903.     

Higher and lower‐level relationships of the deep‐sea fish order Alepocephaliformes (Teleostei: Otocephala) inferred from whole mitogenome sequences

Fishes of the order Alepocephaliformes, slickheads and tubeshoulders, constitute a group of deep‐sea fishes poorly known in respect to most areas of their biology and systematics. Morphological studies have found alepocephaliform fishes to display a mosaic of synapomorphic and symplesiomorphic characters, resulting in great difficulties when attempting to resolve intra‐ and interrelationships. Molecular data recently added to the confusion by removing Alepocephaliformes from the Euteleostei and placed them as incertae sedis within the Otocephala. In the present study we attempt to further clarify relationships of Alepocephaliformes by adding newly determined whole mitogenome sequences from 19 alepocephaliforms in order to address 1) phylogenetic position of Alepocephaliformes within the Otocephala; and 2) intrarelationships of Alepocephaliformes. The present study includes 96 taxa of which 30 are alepocephaliforms and unambiguously aligned sequences were subjected to partitioned maximum likelihood and Bayesian analyses. Results from the present study support Alepocephaliformes as a genetically distinct otocephalan order as sister clade to Ostariophysi (mostly freshwater fishes comprising Gonorynchiformes, Cypriniformes, Characiformes, Siluriformes and Gymnotiformes). The disputed family Bathylaconidae was found to be an artificial assemblage of the two genera Bathylaco and Herwigia, with the former as the sister group of the family Alepocephalidae and the latter nested within Alepocephalidae. Platytroctidae was found to be monophyletic as sister clade to the rest of Alepocephaliformes. Previously unrecognized clades within the family Alepocephalidae are presented and a clade comprising Alepocephalus, Conocara and Leptoderma was recovered as the most derived. As long as the current classification is being followed, the genera Alepocephalus, Bathytroctes, Conocara and Narcetes were all found non‐monophyletic. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 923–936.     

Comparative wood anatomy in Abietoideae (Pinaceae)

This study, which includes 51 species and six genera of subfamily Abietoideae (Pinaceae), assesses the systematic significance of the wood structure in this group. In particular, the presence of normal and traumatic resin canals, the ray structure and the axial parenchyma constitute phylogenetically informative features. Comparative wood anatomy of Abietoideae clearly supports the monophyly of the genera Abies–Cedrus–Keteleeria–Nothotsuga–Pseudolarix–Tsuga, all of which have axial parenchyma with nodular transverse end walls in the regions of growth ring boundaries, crystals in the ray parenchyma and pitted horizontal and nodular end walls of ray parenchyma cells. Axial resin canals support a subdivision of the subfamily into two groups: Abies, Cedrus, Pseudolarix and Tsuga, without axial resin canals, and Keteleeria and Nothotsuga, with axial resin canals and a specific arrangement of traumatic axial resin canals. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 184–196.     

Comparative vegetative anatomy and systematics of the angraecoids (Vandeae, Orchidaceae) with an emphasis on the leafless habit

The vegetative anatomy and morphology of 142 species of the angraecoid orchids (Angraecinae + Aerangidinae) and 18 species of Aeridinae were examined using light and scanning electron microscopy. Leafless members of Vandeae were of particular interest because of their unique growth habit. Leafy and leafless members of Angraecinae and Aerangidinae were examined and compared with specimens of Aeridinae. Vandeae were homogeneous in both leaf and root anatomy. A foliar hypodermis and fibre bundles were generally absent. Stegmata with spherical silica bodies were found associated with sclerenchyma and restricted to leaves in almost all specimens examined. Distinct inner tangential wall thickenings of the endovelamen occurred in several vandaceous genera. Exodermal proliferations and aeration units commonly occurred in both leafy and leafless Vandeae. Cladistic analyses of Angraecinae and Aerangidinae with members of Aeridinae and Polystachyinae as outgroups using 26 structural characters resulted in 20 000+ equally parsimonious trees. Vandeae formed the only well-supported clade in bootstrap analyses and were characterized by having a monopodial growth habit, spherical stegmata, loss of mucilage, and loss of tilosomes.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 165–218.     

Phylogenetic analysis of the Mexican freshwater crabs of the tribe Pseudothelphusini (Decapoda: Brachyura: Pseudothelphusidae)

The Mexican pseudothelphusid crabs are classified in one subfamily, three tribes, and 13 genera. Up to now, 56 species have been recognized, distributed in a strictly Neotropical pattern, with some of them reaching the state of Sonora on the western slope of Mexico. The tribe Pseudothelphusini is the most diverse, with five genera and 35 species, all of them endemic to Mexico: the two most species‐rich genera are Pseudothelphusa, with 23 species, and Tehuana, with eight species; Epithelphusa includes two species, whereas Disparithelphusa and Smalleyus are monotypic. The Pseudothelphusini lack an updated systematic revision, which could serve as a framework to analyse the monophyletic origin of the group, to clarify the relationships among genera and species, as well as to resolve the taxonomic status of various species complexes. In the present study, an exhaustive morphological revision was conducted using somatic and sexual characters. A phylogenetic analysis was performed using 77 characters and 183 character states, taken from 41 species. Ten trees of the same length were obtained using PAUP 4.0 through a heuristic search. The results show that the tribe as it is actually known constitutes a paraphyletic group, in which the species of Epithelphusa and Pseudothelphusa puntarenas are excluded from the internal group. According to the obtained results, the tribe Pseudothelphusini s.s. includes five genera: Smalleyus, Pseudothelphusa, Tehuana, and two new ones to accommodate Pseudothelphusa galloi and Pseudothelphusa sulcifrons, respectively. This new arrangement considers the provisional suppression of the genus Disparithelphusa, which remained as another species of Pseudothelphusa throughout the cladistic analysis. The phylogenetic results show a strong congruence with the distribution of the species, in several cases grouping species that form morphological clines along a geographical gradient. The previously proposed southern origin of the tribe Pseudothelphusini gains support with the results obtained. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 457–481     

A taxonomic revision and pollen morphology of the genus Dendrokingstonia (Annonaceae)

The genus Dendrokingstonia (Annonaceae) is taxonomically revised and palynologically studied. Three species are recognized, one of which, D. gardneri , is described as new to science. One new combination, D. acuminata , is made. The genus occurs from southern Thailand to Peninsular Malaysia and Sumatra. On the basis of macromorphology and pollen characters, it is considered to be related to Monocarpia. Both genera show a combination of macromorphological characters that is rare in the family, i.e. considerably enlarged stigmas, leaves with percurrent tertiary veins, a highly reduced number of carpels per flower and relatively large monocarps with a thick, hard wall. Scanning and transmission electron microscopy show that the pollen grains of Dendrokingstonia and Monocarpia are monosulcate monads with a columellate infratectum and a more or less bulging intine at the sulcus. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168 , 76–90.     

The so‐called primitive genera of Genisteae (Fabaceae): systematic and phyletic considerations based on karyological data

A karyological analysis of the so‐called primitive genera of Genisteae has shown that they have a relatively homogeneous chromosome complement: all species tend to have a somatic chromosome number 2n = 48, which can increase to 2n = 52, presumably as a result of hyperaneuploidy. Karyological data suggest that Argyrocytisus, Cytisophyllum and Petteria may be considered as distinct genera rather than being assigned to Cytisus, with 2n = 52 for the first of these and 2n = 50 for the other two genera. They may be interpreted as relict monotypic genera as a result of the presence of a stabilized aneuploidy. Karyological characters exclude a recent origin of Genisteae from Thermopsideae. On the contrary, they are consistent with the hypothesis that Genisteae and Thermopsideae are independently derived from a basic papilionoid stock, of which present day Sophoreae are the remainder. At least two lines would lead from Sophoreae to the taxa of the ‘genistoid alliance’, one to Thermopsideae and the other ‘podalyrioid alliances’ (Podalyrieae and Mirbelieae), with the prevailing basic number of x = 9, and the other to Genisteae, with a basic number of x = 12 persisting in some present day genera, including Cytisus s.l. From this lineage, a wide range of secondary basic numbers has been formed, mostly by descending aneuploidy. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 232–248.     

Comparative vegetative anatomy and systematics of the Oncidiinae (Maxillarieae, Orchidaceae)

Subtribe Oncidiinae comprises a vegetatively heterogeneous assemblage of species that has persistently been incapable of organization. Anatomy was considered to be a possible means to resolve the perplexity of relationships amongst the constituent taxa. The consistent occurrence of a foliar hypodermis, homogeneous mesophyll, conical silica bodies in stegmata, and ubiquitous fibre bundles in leaves provides a matrix for linking the taxa, as do the parenchymatous pith and O-thickened endodermal cell walls in roots. However, the strict consensus of the 40 genera studied was completely unresolved, suggesting that vegetative characters alone are insufficient to assess the relationships amongst these taxa, a conclusion also reached for the remainder of Maxillarieae.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 91–107.     

Palynological survey of subtribe Pithecocteniinae (Bignonieae,Bignoniaceae)

The pollen morphology of subtribe Pithecocteniinae was reviewed. Thirty species of the six genera currently recognized, namely Amphilophium, Distictis, Distictella, Glaziovia, Haplolophium and Pithecoctenium, were considered. All the species surveyed fell into one of the two pollen groups: (1) inaperturate, spheroid pollen; and (2) stephanocolpate, prolate pollen. The former group included the studied species of Distictis, Distictella and Pithecoctenium, the latter species of Amphilophium, Glaziovia and Haplolophium. The variation of exine sculpture and thickness did not show any taxonomic relationships. An argument for considering pollen features, together with other morphological characters, to elucidate monophyletic units within Pithecocteniinae is presented. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 155–162.     

Vegetative anatomy and systematics of Triphorinae (Orchidaceae)

Triphorinae represents a group of three anatomically simple genera, the structural features of which are unspecialized. The anomocytic stomatal pattern occurs in all genera; it predominates in Triphora. A foliar hypodermis, sclerenchyma, fibre bundles and stegmata are absent. The mesophyll is homogeneous. The exodermal and endodermal cells in the roots are entirely thin‐walled and tilosomes are absent. However, there are anatomical modifications that appear to be unique: root hairs in Monophyllorchis are borne on velamenal buttresses and, in Psilochilus, they arise endogenously. In the root vascular system of Psilochilus, the metaxylem occurs as a circumferential band. The surfaces of stems in Triphora are tuberculate. Mycorrhizae appear to characterize the root cortices of all genera. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 203–210.