Microlicia crassa and M. maculata spp. nov. (Melastomataceae) from Minas Gerais,Brazil: morphology and leaf anatomy

Two new species of Microlicia from campos rupestres of Minas Gerais are described, illustrated and compared with their relatives. Microlicia crassa sp. nov. is similar to M. formosa, and M. maculata sp. nov. is similar to M. isophylla and M. tetrasticha. The trichomes covering both surfaces of the leaves of the two new species and their relative, M. isophylla may be characterized as sessile glands under a stereomicroscope, but anatomical studies revealed the presence of a short stalk. Microlicia crassa and M. maculata are assessed as “Endangered”, according to the IUCN categories and criteria.     

Vegetative anatomy and morphology of Amentiferae

Some of the important vegetative characters of amentiferous families described in research papers concerned with interfamilial relationships and published since 1947–1948 are briefly summarized. Important conclusions by the writers are also reviewed. Thus, Bataceae are considered derivatives of the Centrospermae ; Betulaceae, Casuarinaceae, and Ulmaceae are hamamelidaceous derivatives; Garryaceae and Cornaceae are closely related; and Julianiaceae and Anacardiaceae are plausible relatives. A more extensive tabulation of vegetative characters of essentially all amentiferous and ranalean families and Dilleniaceae is also presented, and the data are utilized to compare the percentages of advanced and primitive characters in these same taxa. The logic for considering trends whose evolutionary directions were initiated previous or incidental to angiospermous origin as more valid than other evolutionary trends is offered. The following principal conclusions are based upon the analysis of the tabulation: (1) the Amentiferae have sufficient advanced vegetative characters to preclude consideration of them as earliest angiosperms or their direct derivatives unless a large number of primitive features of other sorts offers strong counter evidence; (2) they also have sufficient primitive characters to discount the concept that they are highly evolved; (3) most Amentiferae clearly possess many more advanced vegetative characters than do most Magnoliales, Laurales, Trochodendrales, or Dilleniaceae ; and (4) relationships of several Amentiferae to various, unrelated angiospermous families have been demonstrated.     

Comparative leaf anatomy and morphology of some neotropical Rutaceae: Pilocarpus Vahl and related genera

Previous anatomical studies have been restricted to the foliar aspects of Pilocarpus. However, no anatomical studies analyzing the foliar aspects of Pilocarpus in relation to related genera have been carried out. Therefore, the aim of this study was to identify characters for future taxonomic and phylogenetic studies in Rutaceae, particularly in Pilocarpus, and to discuss the characteristics associated with the simple or compound leaf condition for the group. The petiole and the leaf blade of 14 neotropical Rutaceae species were analyzed, and the following characteristics were observed in all leaves studied: stomata on both surfaces; secretory cavities, including mesophyll type; camptodromous?Cbrochidodromous venation pattern; and free vascular cylinder in the basal region of the petiole. Additional promising characters were identified for future taxonomic and phylogenetic studies in the Rutaceae family, especially for the Pilocarpus genera.     

Seed morphology and anatomy in someAnnonaceae

Twelve species ofAnnonaceae, namelyAncana sp.,A. stenopetala, Annona cherimola, A. montana, A. muricata, A. squamosa, Bocagea sp.,Bocageopsis canescens, two species ofUnonopsis, Xylopia aromatica, andX. emarginata, were investigated with respect to the morphology and anatomy of the seed. They show the basic structural pattern characteristic of annonaceous seeds: perichalaza, fibrous mesotesta, and rumination developed by both integuments. However, several differential characters, some of them never previously described, were found: All taxa exhibit an additional endotestal mechanical layer which forms the micropylar plug except inAncana. InAncana the plug is built by the inner integument. Aril, sarcotesta and pits on the seed surface are present in some taxa and show different origin and structure. Special anatomical adaptations possibly functioning during germination are described. The results obtained from the investigated taxa are discussed and compared with published data on seed structure inAnnonaceae.     

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.     

Comparative anatomy of the vegetative organs in Pleiochiton A. Gray (Melastomataceae), with emphasis on adaptations to epiphytism

We present a comparative analysis on the anatomy of roots, shoots, and leaves of three epiphytic Pleiochiton species and a species of the closely related Clidemia. The four species share similar anatomical characters, suggesting adaptations toward water storage in all the structures and, consequently, to the water-limited epiphytic habitat. All four species present succulent roots with up to 75% of its volume with cells that store water. The leaves have about 50% of the volume formed by a hypodermis that also stores water. They are very similar to leaves of epiphytic Peperomia and Gesneriaceae, suggesting evolutionary convergence. Leaf cells in all species have large vacuoles and compact mesophyll, with little intercellular spaces; all these traits are usually related to CAM photosynthesis. The anatomical features found in all four species agree with previous phylogenetic analyses that show Clidemia blepharodes, Pleiochiton ebracteatum and Pleiochiton micranthum as members of a same clade.     

Comparative anatomy, morphology, and molecular phylogenetics of the African genus Satanocrater (Acanthaceae)

? Premise of the study: Anatomical and morphological features of Satanocrater were studied to test hypotheses of xeric adaptations in the genus, which is endemic to arid tropical Africa. These features, together with molecular data, were used to test the phylogenetic placement of Satanocrater within the large plant family Acanthaceae. ? Methods: We undertook a comparative study of four species of Satanocrater. Carbon isotope ratios were generated to test a hypothesis of C(4) photosynthesis. Molecular data from chloroplast (trnG-trnS, trnG-trnR, psbA-trnH) and nuclear (Eif3E) loci were used to test the placement of Satanocrater within Acanthaceae. ? Key results: Anatomical features reflecting xeric adaptations of species of Satanocrater included a thick-walled epidermis, thick cuticle, abundant trichomes and glandular scales, stomata overarched by subsidiary cells, tightly packed mesophyll cells, and well-developed palisade parenchyma on both leaf surfaces. Although two species had enlarged bundle sheath cells, a feature often implicated in C(4) photosynthesis, isotope ratios indicated all species of Satanocrater use the C(3) pathway. Molecular data resolved Satanocrater within tribe Ruellieae with strong support. Within Ruellieae, our data suggest that pollen morphology of Satanocrater may represent an intermediate stage in a transition series. ? Conclusions: Anatomical and morphological features of Satanocrater reflect adaptation to xeric environments and add new information about the biology of xerophytes. Morphological and molecular data place Satanocrater in the tribe Ruellieae with confidence. This study adds to our capacity to test hypotheses of broad evolutionary and ecological interest in a diverse and important family of flowering plants.     

Comparative seed morphology of <Emphasis Type="Italic">Leandra</Emphasis> (Miconieae,Melastomataceae)

The seed morphology of 79 species of neotropical Miconieae (Melastomataceae) is presented. These species have been chosen, in majority, from the polyphyletic genus Leandra. A few other species from the polyphyletic genera Miconia, Ossaea, and Clidemia were also sampled, because of potential similarities. Sixteen morphological seed types are defined after analysis through light microscopy and scanning electron microscopy. The seed morphology appears to possess a great deal of variability on the level of the overall shape as well as the structure and the surface of the testa. The different types defined here do not match with genera or sections, but rather are composed of species coming from different genera. In comparison with a preliminary molecular phylogeny study done on Leandra, some types of seeds are related to well supported clades. In some cases seed morphology corresponds with natural groups of species, thus being of high phylogenetic importance.     

Gross brain morphology of Hypoptopomatinae and Neoplecostominae (Siluriformes: Loricariidae): Comparative anatomy and phylogenetic implications

Hypoptopomatinae and Neoplecostominae include about 250 valid species, a substantial portion of loricariid catfishes. Although the relationships among the members of these subfamilies have been inferred by many authors, the most recent hypotheses based on morphological and molecular data differ widely. Herein, we provide new data on the morphology of the central nervous system, and evaluate the usefulness of these characters in phylogenetic inference. To accomplish this, we characterized the gross brain morphology of those catfishes, and analyzed 54 neuroanatomical characters in a total of 40 terminal taxa representing Hypoptopomatinae and Neoplecostominae, and also members of Delturinae and Hypostominae as outgroups. Hypoptopomatinae and Neoplecostominae are recovered as separate subfamilies, and most of our results are compatible with morphology‐based analyses. We conclude that neuroanatomy provides an informative source of new characters with strong phylogenetic signal at all recovered taxonomic levels.     

Comparative anatomy and morphology of Vitis vinifera (Vitaceae) somatic embryos from solid- and liquid-culture-derived proembryogenic masses

Ontogeny of somatic embryos of grapevine (Vitis vinifera) produced from solid- and liquid-culture-derived proembryogenic masses (PEM) was compared using light and scanning electron microscopy. Somatic embryos produced from solid-medium-derived PEM (SPEM) had large cotyledons, little or no visible suspensor structure, and a relatively undeveloped concave shoot apical meristem, whereas those from liquid-medium-derived PEM (LPEM) had smaller cotyledons, a distinct suspensor, and a flat-to-convex shoot apical meristem. The convex shoot apical meristem in LPEM-derived somatic embryos formed as early as the heart stage of development; it was 4-6 cell layers deep and rich in protein. Suspensors persisted in fully developed and mature LPEM-derived somatic embryos. The SPEM-derived somatic embryos exhibited dormancy, as do mature zygotic embryos, which also have a rudimentary suspensor, whereas LPEM-derived embryos were not dormant. We hypothesize that the presence of a persistent suspensor in LPEM-derived somatic embryos modulates development, ultimately resulting in rapid germination and a high plant-regeneration rate.     

Comparative morphology,anatomy and palynological studies of perennial species of Onobrychis (Fabaceae) in northeast Iran

This study examined morphological, anatomical and palynological characters for six species, two subspecies and two varieties of perennial Onobrychis growing in northeast Iran. In the morphological study, shape, size and color of vegetative organs and legumes were assessed. For the anatomical study, cross sections of mature fresh or dried stems, leaflets and petioles were prepared and stained. In the palynological study, pollen were extracted, acetolysed and observed by SEM. The morphological study indicated that some characteristics varied among species, such as shape of stipules and calyx teeth, color and shape of corolla segments and legumes and an identification key is provided based on these characters. Also, in internal structure some differences were noticed in the shape of petiole cross sections, the thickness of cortex and pith shape in petioles and the arrangement of vessels in stems. Some anatomical characters proved useful to identify species, but not sections. Palynological results showed circular and obtuse triangular pollen in polar view and elliptical pollen in equatorial view with reticulate ornamentation. In addition, a cluster analysis was done based on morphological, anatomical and palynological features. The resulting dendrogram confirmed the taxonomic treatment suggested by Sirjaev and Rechinger.     

Comparative wood anatomy ofCoriaria

Wood anatomy ofCoriaria was surveyed to clarify generic features on the basis of 14 species collected from various regions of the World to cover the whole range of geographic distribution and habitual variation. Wood anatomy ofcoriaria is considerably uniform, and the species share a combination of the following features: 1) pores are thin-walled, polygonal in outline and mostly in multiples; 2) vessel elements and libriform fibers are very short; 3) perforation plates are exclusively simple; 4) intervessel pits are alternate; 5) vascular tracheids are present; 6) wood parenchyma is vasicentric and sometimes confluent; 7) rays are heterogeneous and large. Its species differ in several characters, such as distinctness of growth rings, pore size, pore patterns, type and abundance of wood parenchyma, and distinctness of storied structure. Comparisons among species indicate that the species of the Northern Hemisphere show a tendency toward having semi-ring porosity, while those of the Southern and Western Hemisphere have diffuse porosity. The other infrageneric variations appear to be related to different habits of the species rather than to geographic distribution. Small trees mostly have confluent and vasicentric parenchyma composed of fusiform cells and distinctly storied tissues, while shrubs and herbs have less abundant parenchyma which is vasicentric and comprises strands of two to four cells and indistinctly storied tissues.     

Comparative floral anatomy of Pontederiaceae

Floral anatomy is described in eight species (representing five genera) of Pontederiaceae, and floral ontogeny is described in Pontederia cordata. The results are assessed in the context of recent phylogenetic work on Pontederiaceae, which indicates that the unilocular ovary condition has been achieved by two different, non-homologous routes in Pontederiaceae: via loss of interlocular septa in Heteranthera and Hydrothrix , and via pseudomonomery in Pontederia , which has a single fertile carpel. Absence of septal nectaries has evolved more than once in Pontederiaceae, at least in Heterantha and Monochoria , probably due to a transfer of the insect reward from nectar to pollen in these taxa. The presence of an elliptical or linear unvascularized appendage on the abaxial outer stamen in Monochoria is also probably correlated with enantiostyly. In Pontederia , air spaces in the ovary wall are modified into canals, each with a ring of apparently secretory epithelial cells.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 395–408.     

Comparative gross anatomy of ratites

The four most common ratites kept in captivity, emus, rheas, ostriches, and cassowaries, share similar musculoskeletal features based on their common evolution to a flightless form. However, they differ in body size and coloration, wing size relative to entire body size, extent of leg feathering, and number of toes. During necropsies we observed the differences among the birds, which include the shape of tongue and tonsils, a tracheal cleft found only in emus, varied shapes of the thymus, spleen, bursa of Fabricius, proventriculus, duodenal loop, and ceca, different lengths of colon and ceca relative to the entire intestinal length, and different coloration of the gonads. Several of the structural differences reflect the phylogeny of the ratites. Rheas and ostriches share common features in relatively large wings, kidney-bean shaped spleen, tan gonads, and long ceca, whereas emus and cassowaries have relatively small wings, short ceca, and similar proventriculi. The anatomical variations may reflect their varied diets in the wild and the different behaviors among the groups such as their characteristic vocalizations. Knowledge of the differences may be useful in formulating proper diets for captive birds and is important for the recognition of clinically normal structures in the ratites.     

Comparative anatomy of conifer leaves

The epidermis and internal structure of 103 species and 8 varieties of conifer leaves belonging to 37 genera of 7 families have been comparatively investigated. The anatomical characters of leaves of all the genera (or sections) studied are described systematically and a key to the genera (or sections) is also presented. It is shown that in order to identify at the genus level, the leaf types of LaubenFels’ may be used as the primary characterization. And it can also be seen that the following characters which are relatively constant at the genus level provide an important basis for identification: the epidermal structure, the presence or absence of hypodermis, the degree of differentiation of mesophyll, the occurrence of vascular bundle sheath or endodermis, the transfusion tissue type, the number and relative spatial position of vascular bundles, the number and distribution of resin canal and the presence of sclereid or sclerenchyma. The genera of Cupressaceae (except for Juniperus and Sabina) are of scale leaves (Leaf type-III) with little differences in structural characters. It’s difficult to distinguish them from each other. In addition, some problems concerning the significance of the resin canal, the endodermis with Casparian-strip, the sclerenchyma and the vascular bundle in identificationare here also discussed.     

Studies in the floral morphology and anatomy of nymphaeales

Floral morphology ofBrasenia schreberi Gmel. andCabomba caroliniana A. Gray was observed chiefly from an anatomical point of view. The receptacle ofB. schreberi is rather flat and a vascular plexus is observable in the mature flower. The vasculature in this plexus is so complex taht it is not easy to trace its structure in detail. by observation on small buds, it can be seen that the receptacular vasculature consists of a girdling bundle in the basal area and usually nine receptacular strands from which traces to the petals and stamens branch off. The vasculature in the receptacle is reconstructed and diagramatically shown as though split longitudinally and spread out in one plane. Floral vasculature inCabomba caroliniana is simpler, and is probably related to the smaller number of stamens and carpels. It also has a girdling bundle at the bottom of receptacle and this vasculature is suggested to be derived by simplification from aBrasenia-type vasculature. Evidence from floral anatomy suggests that these two genera are closely related. InNymphaea, a vascular plexus in the receptacle is also observed (Moseley, 1961; Ito 1983). The plexus ofBrasenia andNymphaea are not the same in their construction. Nevertheless, their fundamental floral vasculature is comparable and it is preferable to place them in the same family or same order.