Floral anatomy and systematic position ofVivianiaceae

The floral anatomy of four species ofViviania has been studied. In the basic floral plan and essential floral anatomical featuresViviana closely resembles theGeraniaceae. Evidence from vegetative and floral anatomy, ultrastructural studies on phloem as well as phytochemistry supports geranialean affinity ofViviania; the placement within thePittosporales sensuHutchinson being unnatural.     

Floral anatomy ofHypseocharis (Oxalidaceae) with a discussion on its systematic position

The floral anatomy of threeHypseocharis spp. has been studied. The genus resemblesOxalidaceae as well asMonsonia andSarcocaulon of theGeraniaceae. As it is closer toGeraniaceae than toOxalidaceae, it perhaps serves as a connecting link between them.     

Comparative anatomy of the young stem,node, and leaf of Bonnetiaceae,including observations on a foliar endodermis

A comprehensive study of the nodal and leaf anatomy of Bonnetiaceae was completed in order to provide evidence for evaluation in relation to systematics. Nodal anatomy is trilacunar, three-trace or unilacunar, one-trace. Basic leaf anatomical features of the family include: complete or incomplete medullated vascular cylinder in petiole; paracytic mature stomata with encircling ridges; large mucilaginous cells in the adaxial surface of mesophyll; periclinal divisions in upper surface layers; and discrete patches of phloem within the vascular bundles. Especially noteworthy is the presence in some genera of foliar vascular bundles enveloped by a sheath composed of two concentric regions, i.e., an inner region consisting of multiple layers of fibers and an outer specialized endodermis composed of thin-walled cells with Casparian strips. Leaves are variable with respect to lamina and cuticle thickness, relative amount and number of palisade and spongy layers, venation of lamina, and the presence or absence of sclereids and crystals in the mesophyll. A major feature in the evolution of Bonnetiaceae is development of a highly divergent, essentially parallel, leaf venation that is superficially similar to that of some monocotyledons and apparently unique among dicotyledons. Foliar anatomy provides important characters for the recognition of subgroups within Bonnetiaceae and is consistent with the segregation of Bonnetiaceae from Theaceae.     

Seed-coat anatomy of the non-pleurogrammic seeds in the tribe Ingeae (Leguminosae,Mimosoideae)

An anatomically complex structure of the seed-coat is a general characteristic of all members of the Leguminosae. Nonetheless, certain genera exhibit a particular type of seed, the “overgrown” seen that has been defined by a developmental criterion and by more simple anatomical features of the seed-coat. Only the last criterion seems suitable for unambiguously distinguishing this type of seed, which is here referred to as “overgrown-like.” This type appears to be apomorphic in the Ingeae (and probably in all the Leguminosae) and likely results from a heterochronic loss of tissue differentiation. Variations in this character may be useful at the generic level, and detailed anatomical observations reveal the occurrence of three distinct patterns. The high degree of correlation with other characters suggests that overgrown-like seeds have evolved separately at least three times in the Ingeae and thatPithecellobium s.s. may be polyphyletic. The overgrown-like seeds are likely to be an adaptive response to wet tropical climates.     

Gross and fine anatomy of the respiratory vasculature of the mudskipper,Periophthalmodon schlosseri (Gobiidae: Oxudercinae)

To illustrate vascular modification accompanying transition from aquatic to amphibious life in gobies, we investigated the respiratory vasculatures of the gills and the bucco‐opercular cavities in one of the most terrestrially‐adapted mudskippers, Periophthalmodon schlosseri, using the corrosion casting technique. The vascular system of Pn. schlosseri retains the typical fish configuration with a serial connection of the gills and the systemic circuits, suggesting a lack of separation of O₂‐poor systemic venous blood and O₂‐rich effluent blood from the air‐breathing surfaces. The gills appear to play a limited role in gas exchange, as evidenced from the sparsely‐spaced short filaments and the modification of secondary lamellar vasculature into five to eight parallel channels that are larger than red blood cell size, unlike the extensive sinusoidal system seen in purely water‐breathing fishes. In contrast, the epithelia of the bucco‐opercular chamber, branchial arches, and leading edge of the filaments are extensively laden with capillaries having a short (<10 μm) diffusion distance, which strongly demonstrate the principal respiratory function of these surfaces. These capillaries form spiral coils of three to five turns as they approach the epithelial surface. The respiratory capillaries of the bucco‐opercular chamber are supplied by efferent blood from the gills and drained by the systemic venous pathway. We also compared the degree of capillarization in the bucco‐opercular epithelia of Pn. schlosseri with that of the three related intertidal‐burrowing gobies (aquatic, non‐air‐breathing Acanthogobius hasta; aquatic, facultative air‐breathing Odontamblyopus lacepedii; amphibious air‐breathing Periophthalmus modestus) through histological analysis. The comparison revealed a clear trend of wider distribution of denser capillary networks in these epithelia with increasing reliance on air breathing, consistent with the highest aerial respiratory capacity of Pn. schlosseri among the four species. J. Morphol. 2011. © 2011 Wiley‐Liss, Inc.     

Floral anatomy of the Lecointea clade (Leguminosae, Papilionoideae, Swartzieae sensu lato)

Flower and inflorescence anatomy and morphology of Exostyles, Harleyodendron, Holocalyx, Lecointea, and Zollernia (Leguminosae, Lecointea clade) were studied. Features common to all genera but otherwise rare within the Leguminosae include: (1) the presence of phenolic compounds in the epidermal cells of the anthers and subepidermal cells of the bracteoles, sepals, petals, and ovaries (absent in Holocalyx balansae); (2) simple trichomes on the adaxial base of the bracteoles and on the surface of the calyx and ovaries; and (3) tapetum persisting until the androspores are formed. Other notable anatomical features are: (1) colleters on the adaxial bases of the bracts and bracteoles of Holocalyx balansae and Zollernia ilicifolia; (2) trichomes on the anthers of Harleyodendron unifoliolatum, Holocalyx balansae, Lecointea hatschbachii, Zollernia ilicifolia and Z. magnifica; (3) osmophores on the petals of Exostyles godoyensis; (4) asynchronous pollen development in the anthers of Holocalyx balansae and Zollernia magnifica; and (5) vascular bundles surrounded by lignified fibers in Harleyodendron unifoliolatum. These anatomical characters are discussed according to their possible phylogenetic implications.     

Floral anatomy of Paepalanthoideae (Eriocaulaceae, Poales) and their Nectariferous structures

BACKGROUND AND AIMS: Eriocaulaceae (Poales) is currently divided in two subfamilies: Eriocauloideae, which comprises two genera and Paepalanthoideae, with nine genera. The floral anatomy of Actinocephalus polyanthus, Leiothrix fluitans, Paepalanthus chlorocephalus, P. flaccidus and Rondonanthus roraimae was studied here. The flowers of these species of Paepalanthoideae are unisexual, and form capitulum-type inflorescences. Staminate and pistillate flowers are randomly distributed in the capitulum and develop centripetally. This work aims to establish a floral nomenclature for the Eriocaulaceae to provide more information about the taxonomy and phylogeny of the family. METHODS: Light microscopy, scanning electron microscopy and chemical tests were used to investigate the floral structures. KEY RESULTS: Staminate and pistillate flowers are trimerous (except in P. flaccidus, which presents dimerous flowers), and the perianth of all species is differentiated into sepals and petals. Staminate flowers present an androecium with scale-like staminodes (not in R. roraimae) and fertile stamens, and nectariferous pistillodes. Pistillate flowers present scale-like staminodes (except for R. roraimae, which presents elongated and vascularized staminodes), and a gynoecium with a hollow style, ramified in stigmatic and nectariferous portions. CONCLUSIONS: The scale-like staminodes present in the species of Paepalanthoideae indicate a probable reduction of the outer whorl of stamens present in species of Eriocauloideae. Among the Paepalanthoideae genera, Rondonanthus, which is probably basal, shows vascularized staminodes in their pistillate flowers. The occurrence of nectariferous pistillodes in staminate flowers and that of nectariferous portions of the style in pistillate flowers of Paepalanthoideae are emphasized as nectariferous structures in Eriocaulaceae.     

The genusBrachydesmiella from submerged wood in the tropics, including a new species and a new combination

During studies of fungi occurring on wood submerged in freshwater streams in the tropics, five species ofBrachydesmiella, namely,B. anthostomelloidea, B. biseptata, B. caudata, B. orientalis comb. nov., andB. verrucosa sp. nov., were collected. There are described and illustrated from natural substrata, wooden test blocks, and from pure culture, based mainly on collections made in Thailand.Brachydesmiella verrucosa differs from the other four species in having 3-celled, coarsely verrucose, ampoule-shaped conidia, with a long, thin, cylindrical, verruculose apical cell. A key toBrachydesmiella species is provided.     

Delimitation of the Thoracosphaeraceae (Dinophyceae), including the calcareous dinoflagellates, based on large amounts of ribosomal RNA sequence data

The phylogenetic relationships of the Dinophyceae (Alveolata) are not sufficiently resolved at present. The Thoracosphaeraceae (Peridiniales) are the only group of the Alveolata that include members with calcareous coccoid stages; this trait is considered apomorphic. Although the coccoid stage apparently is not calcareous, Bysmatrum has been assigned to the Thoracosphaeraceae based on thecal morphology. We tested the monophyly of the Thoracosphaeraceae using large sets of ribosomal RNA sequence data of the Alveolata including the Dinophyceae. Phylogenetic analyses were performed using Maximum Likelihood and Bayesian approaches. The Thoracosphaeraceae were monophyletic, but included also a number of non-calcareous dinophytes (such as Pentapharsodinium and Pfiesteria) and even parasites (such as Duboscquodinium and Tintinnophagus). Bysmatrum had an isolated and uncertain phylogenetic position outside the Thoracosphaeraceae. The phylogenetic relationships among calcareous dinophytes appear complex, and the assumption of the single origin of the potential to produce calcareous structures is challenged. The application of concatenated ribosomal RNA sequence data may prove promising for phylogenetic reconstructions of the Dinophyceae in future.     

The anatomy of the cypselae of species of Cineraria L. (Asteraceae–Senecioneae) and its taxonomic significance

CRON, G. V., ROBBERTSE, P.J. & VINCENT, P. L. D., 1993. The anatomy of the cypselae of species of Cineraria L. (Asteraceae–Senecioneae) and its taxonomic significance. The anatomy of the cypselae of five species of Cineraria has been investigated to establish its potential usefulness for interspecific taxonomy. The usefulness is apparently limited. The most useful characters are the number of ribs, the extent of sclerenchymatization of the ribs and wings, and the surface sculpturing of the epicarp cells. The shape and symmetry of the cypselae are also useful to a limited degree. The presence of three resin canals in each cotyledon is constant. Their spatial differentiation is described.     

Preantral intra-ovarian oocyte release in the white-footed mouse,Peromyscus leucopus

Summary Optical diffraction analysis was carried out on crystalline inclusions in the rough endoplasmic reticulum of the insulin and somatostatin cells in the islet organ of the hagfish. A striking difference in crystalline arrangement was observed between the inclusions of the insulin and somatostatin cells. The crystallographic arrangement of the inclusions observed in situ in the insulin cells differed from that previously found by means of X-ray diffraction analyses of hagfish insulin crystals formed in vitro.     

Floral development and anatomy of Dirachma socotrana, (Dirachmaceae): a controversial member of the Rosales

The floral development and anatomy of Dirachma has been investigated with SEM and LM to discuss the relationship of Dirachmaceae with putative sister taxa (e.g. Rhamnaceae, Malvaceae, Barbeyaceae, Elaeagnaceae) on the basis of morphological synapomorphies. Flowers are initiated in axillary position on terminal branches. An epicalyx consisting of six to eight bracteoles surrounds the valvate calyx. Petal initiation is strongly retarded and primordia arise independently opposite the stamen primordia. The carpels arise independently and become weakly fused at the base; a single ovule develops in an axile position. A hypanthium develops by interprimordial growth between petals and stamens. Nectaries arise in a pouch and are covered with trichomes positioned on a protuberance at the base of the petal. It is suggested that the solitary flowers are derived from compound cymose inflorescences. Comparison between Dirachma and species of Rhamnaceae demonstrates striking similarities in floral structure and anatomy. However, several characters are unique to Dirachma and support a family Dirachmaceae separate from Rhamnaceae.We thank Frieda Christie for technical assistance with the SEM and LM preparations. We very much appreciate the constructive comments of Peter Endress and Paula Rudall.     

Floral anatomy,embryology, seed,and fruit development in Cephalanthus (Naucleeae-Rubiaceae), with emphasis on C. glabratus

Information on the reproductive anatomy in genera of the tribe Naucleeae, particularly Cephalanthus, is scarce and fragmented. Of the six species in the genus, only the mature megagamethophyte of Cephalanthus occidentalis has been described. This study aims to provide information on embryological aspects in flowers of C. glabratus and to analyze the morphology and anatomy of the flowers, fruit, and seed in the six species of the genus. Cephalanthus glabratus have imperfect flowers: pistillate (PF) and staminate (SF). In the PF, the ovules are functional, while in the SF, they atrophy during the formation of the embryo sac. The mature ovule has a single integument, corresponds to the Phyllis type and the embryo sac is a Polygonum type, forming only in the PF. The presence of pollenkitt and secondary presentation of pollen were observed in the SF, as well as in the pollen formation previously described, whereas in the PF, they are absent, due to the collapse of the pollen grains inside the indehiscent anthers. The analysis of the ontogeny of the ovular excrescence in C. glabratus determined its funicular origin, calling it an aril. Its development is a pre-anthesis event, initiated during megasporogenesis. In seeds, the aril is a fleshy, white appendage which almost completely envelops the seeds of Cephalanthus, except for Cephalanthus natalensis where it is noticeably more reduced. Studies of the fruit in Cephalanthus species indicate that the infructescence is a dry schizocarp which separates into uni-seminated mericarps, except in C. natalensis that has fleshy indehiscent fruit.

     

Floral anatomy of Bromeliaceae, with particular reference to the evolution of epigyny and septal nectaries in commelinid monocots

Floral anatomy is described in ten genera of Bromeliaceae, including three members of subfamily Bromelioideae, three Tillandsioideae, and four genera of the polyphyletic subfamily Pitcairnioideae (including Brocchinia, the putatively basal genus of Bromeliaceae). Bromeliaceae are probably unique in the order Poales in possessing septal nectaries and epigynous or semi-epigynous flowers. Evidence presented here from floral ontogeny, vasculature, and the relative positions of nectary and ovules indicates that there could have been one or more reversals to apparent hypogyny in Bromeliaceae, although this hypothesis requires a better-resolved phylogeny. Such evolutionary reversals probably evolved in response to specialist pollinators, and in conjunction with other aspects of floral morphology of Bromeliaceae, such as the petal appendages of some species. The ovary is initiated in an inferior position even in semi-epigynous or hypogynous species. The ovary of all so-called hypogynous Bromeliaceae is actually semi-inferior, because the septal nectary is infralocular; in these species the nectaries have a labyrinthine surface and many vascular bundles. Brocchinia differs from most other fully epigynous species in that each carpel is secretory at the apex and reproductive, rather than secretory, at the base.     

New observations on the innervation of striated ducts in submandibular glands of cats,including possible peptidergic nerves

Summary The presence of hypolemmal axons between striated duct cells in submandibular glands of cats has been established electron microscopically. Axons were found between light cells, between light and dark cells and between light and basal cells. Hypolemmal axons were observed most frequently in the junctional region between striated and intercalary ducts. They were often more common in younger animals. Dark cells with numerous processes sometimes appeared to have a special relationship with hypolemmal axons.Most of the hypolemmal axons in striated ducts contained characteristic agranular vesicles of the cholinergic type, about 40 nm in diameter; many of these axons also contained large dense cored vesicles of the peptidergic type, about 100 nm in diameter and possessing a more clear outer halo. No adrenergic axons have been observed beneath the basal lamina of striated ducts, even after use of 5-OHDA.The possibility that some of the hypolemmal axons in striated ducts are peptidergic and their possible functions are discussed. Apart from other activities these axons may have a role in supplying special trophic factors to the cells, helping them in their developmental specialisation and maintaining them in normal condition. An absence of such factors after parasympathetic decentralisation may be responsible for the dramatic atrophic changes in striated duct cells, especially since the atrophy in the gland is not solely due to an absence of acetylcholine activation.Supported by an M.R.C. GrantThis work has been helped by the technical assistance of Mr. P.S. Rowley