Composition of epicuticular wax layer of two species of Mandevilla (Apocynoideae,Apocynaceae) from Rio de Janeiro,Brazil

The chemical composition of epicuticular waxes of Mandevilla guanabarica and Mandevilla moricandiana was comparatively analyzed by extraction in n-hexane and chloroform. The mean wax content per unit of leaf area in the n-hexane extract was about 13–30 μg cm⁻² for M. guanabarica, containing 20–28% n-alkanes and 55–63% triterpenes; for M. mori-candiana, the mean content was 19 μg cm⁻², containing 73% n-alkanes and 14% triterpenes. In the chloroform extract, the wax yield was 40–80 μg cm⁻² for M. guanabarica, with about 9–11% n-alkanes and 75–82% triterpenes; while for M. moricandiana, the wax yield was 110 μg cm⁻², with 52% n-alkanes and 14% triterpenes. The major compounds identified were lupeol, pentacyclic triterpenes of the α- and β-amyrin class, and n-alkanes such as nonacosane, hentriacontane and tritriacontane. These results indicate that the quantitative chemical profiles of epicuticular waxes of M. guanabarica and M. moricandiana are distinct and could be used as an additional feature in taxonomic identification.     

Anatomy and histochemistry of colleters in Roupelia grata (Apocynaceae)

The colleters of Roupelia grata are present on the petiole of the leaf, bract, bracteole and calyx. A mature colleter has a distinct head and a stalk. The parenchymatous central core is surrounded by epithelial cells. The senescence of the colleter occurs at its apex first and then proceeds towards the base.     

The structure of colleters in several species of Simira (Rubiaceae)

BACKGROUND AND AIMS: Colleters are secretory structures consisting of a parenchymatic middle axis surrounded by a layer of palisade-like epidermal cells. Colleters occur in a large number of rubiaceous species. Their function is to protect the developing shoot apex. They are also taxonomically useful in the Rubiaceae. This study characterized the structure of the colleters of Simira glaziovii, S. pikia and S. rubra and the biochemistry of secretions in S. glaziovii. METHODS: Stipules of the shoot apices of the three species studied were collected at Barragem de Saracuruna, in Rio de Janeiro state, Brazil. The samples were fixed according to the usual methods for light and electron microscopy. Secretion stipules of S. glaziovii were washed with 0.1 m Tris-HCl plus 0.1 %Triton X-100 to extract proteins and carbohydrates. KEY RESULTS: Colleters in these species are located at the base of the stipule. Each species shows a different pattern of distribution. They form as emergentia from the stipules. Simira glaziovii was different from the other two species because it exhibited vascular traces. The epidermal cells of colleters have dense cytoplasm, nuclei, small vacuoles, endoplasmic reticulum, Golgi apparatus, mitochondria and extraplasmic spaces if they are secretory. The outer cell wall of the mature colleters differs from the outer cell wall of stipule cells and immature colleters. Both carbohydrates and proteins were found in secretions from the stipules of S. glaziovii. CONCLUSIONS: Few ultrastructural differences were noted among the three species. These secretory structures not only protect the shoot apex, but also have taxonomic importance below the genus level.     

A new species of Thenardia (Apocynaceae,Apocynoideae) from Chiapas,Mexico, with notes on the genus

A new species,Thenardia chiapensis, is described and illustrated. The new species is the first taxon in the genus to have its fruits, two fused follicles, described and illustrated. In addition, observations ofT. floribunda specimens have revealed the existence of a novel character, coiled filaments, previously undescribed for the genus.     

A new species of Aspidosperma Mart. (Apocynaceae) from Bahia, Brazil

A new species,Aspidosperma thomasii, collected in the vicinity of Uruçuca is described. It belongs to subgenusAspidosperma sectionAspidosperma and is closely related to theA. parvifolium A. DC. group.     

Anatomical structure and secretion compounds of colleters in nine Ilex species (Aquifoliaceae) from southern South America

In order to clarify whether the structures observed at the base of the petiole of the genus Ilex are colleters resulting from stipules, the anatomy, vascularization and secretions of these supposed glandular structures were analysed in nine species. This is the first report of colleters in Ilex. Stipular colleters replace the stipules in all species studied and are characterized by the presence of vascular traces. In addition to the stipular colleters, three other types of colleter were distinguished: standard and lachrymiform colleters found on the leaf teeth or crenations, and sessile colleters found on the margins of the floral bracts. Their basic structure consists of a central core of parenchymatous cells surrounded by one layer of palisade secretory epidermal cells. Histochemical tests were also performed on secretions; proteins were found in the secretions studied, but glucose was not. The glandular origin of the stipular colleters is confirmed on the basis of their position, secretions and anatomy. Analyses of the colleter‐secreted proteins distinguished two different groups of Ilex species. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 197–210.     

Underground system of Mandevilla atroviolacea (Stadelm.) Woodson (Apocynaceae,Apocynoideae) from the Brazilian high-altitude grassland

The underground systems of plants show the most varied structures adapted to survival in unfavorable environmental conditions. For instance, long-term droughts may induce the development of either water and reserve substances or vegetative propagation structures. Since Mandevilla atroviolacea is a species found at high altitudes on rocky outcrops, this study aimed to provide information on the morpho-anatomy of the underground system of this species that may assist in understanding the adaptive strategies at play. Samples from the underground system of three young and two mature plants collected in the field were sectioned and processed according to standard plant anatomical techniques. The upper area of the underground system corresponds to a xylopodium, while the lower is a tuberous stem organ. Tuberous roots account for the majority of the underground system. The increase in tuberous root diameter results from the action of a typical cambium. The high shoot-forming potential and storage of water and reserve substances observed in the underground system of this species are important strategies for it to survive in this habitat.     

A new species of Rhytidocaulon (Apocynaceae) from Somalia

Rhytidocaulon baricum, sp. nov., from open rocky limestone slopes in northeastern Somalia, is described and illustrated.     

Tribal and intergeneric relationships of Mesechiteae (Apocynoideae, Apocynaceae): evidence from three noncoding plastid DNA regions and morphology

The Neotropical tribe Mesechiteae (Apocynaceae) is currently considered to include nine genera: Allomarkgrafia, Galactophora, Macrosiphonia, Mandevilla, Mesechites, Quiotania, Secondatia, Telosiphonia, and Tintinnabularia. Tribal and intergeneric relationships, however, are in dispute. To test the monophyly of the tribe and evaluate intratribal relationships, a maximum parsimony analysis was conducted based on DNA sequences from the plastid rpl16 intron, rps16 intron, and trnS-G intergenic spacer region as well as morphological data for 23 taxa of Mesechiteae and 11 taxa from other tribes of Apocynoideae. Mesechiteae, as currently circumscribed, was found to be polyphyletic. Only removal of Secondatia and Galactophora and inclusion of Forsteronia rendered the tribe monophyletic. Thus defined, Mesechiteae forms a strongly supported clade including seven genera in three subclades: the Mesechites subclade (comprising Tintinnabularia, Allomarkgrafia, and Mesechites), the Forsteronia subclade (containing only Forsteronia) and the Mandevilla subclade (comprising Macrosiphonia, Mandevilla, and Telosiphonia). Allomarkgrafia is nested in Mesechites. Macrosiphonia and Telosiphonia form two distinct monophyletic clades. Both, however, are nested in Mandevilla. Results suggest upholding the following genera in Mesechiteae: Allomarkgrafia, Forsteronia, Mandevilla, Mesechites, and Tintinnabularia. The status of Quiotania could not be evaluated.     

A new species of Cryptolepis (Periplocoideae, Apocynaceae) from Arabia

A new species of Cryptolepis from Yemen, Arabian Peninsula, C. yemenensis is described and figured. It is recognized by the glabrous appearance of the plant, oblong-elliptic to narrowly obovate leaves, small flowers, small follicles and ridged seed. The new species resembles Cryptolepis gillettii Hutch. & E.A. Bruce and C. volubilis (Balf f.) Schwartz to some extent. Their flowers are die, except for size and different corona shapes. However, they differ with regard to the shape and size of the follicles, the texture of the seed coat and the absence or presence of vesture on the plants.     

Supercritical CO2 extraction of velutinol A from Mandevilla velutina (Apocynaceae) cultured cells and MALDI-TOF MS analysis

MALDI-TOF MS analysis of supercritical CO₂ extracted samples obtained from Mandevilla velutina cell cultures allowed the detection of the anti-bradykinin pregnanic steroid, velutinol A, using low amount of sample (1 g lyophilized cells), with minimum analyte isolation.     

New species of Malouetia (Apocynaceae): A trio from Amazonia

Three new species ofMalouetia (Apocynaceae) are described and illustrated:M. amazonica andM. pumila from Brazil andM. gentryi from Peru.Malouetia amazonica grows in inundated igapó forest, whereas the other two are found in non-inundated habitats:M. pumila incampa fechada, andM. gentryi in upland forest.     

Two new species of Microlicia D.Don (Melastomataceae) from campos rupestres in eastern Brazil

Two new species of Microlicia (Melastomataceae) endemic to campos rupestres in Serra do Cipó, Minas Gerais, Brazil, are described, illustrated and compared with their putative relatives. Microlicia rugosa sp. nov. is similar to M. minutiflora and M. martiana by having fastigiate branches, ascending, lanceolate or oblanceolate leaves with obtuse apex, attenuate base and entire margin, flower with short pedicels (1?2 mm long), magenta petals, and dimorphic stamens. Microlicia rugosa is further characterized by wrinkled surface of hypanthium and sepals, and both leaf surfaces with distinct depressions, which sometimes contain short‐stalked glandular trichomes. Microlicia viscida sp. nov. is similar to M. martiana, M. furnensis and M. rugosa mainly by having fastigiate branches, terete stems without leaves at the base and the bark gradually peeling to reveal the underlying brownish wood and leaves with similar size and shape. Microlicia viscida is characterized by a conspicuous secretion covering branches, leaves, hypanthium and sepals, giving a smooth and bright appearance. The leaf anatomy of both new species is briefly described. Microlicia rugosa and M. viscida are assessed as ‘Endangered’ and ‘Critically Endangered’ respectively, due to its limited extent of occurrence and area of occupancy, according to the IUCN categories and criteria.     

Ontogenesis secretion and senescence of Tocoyena bullata (Vell.) Mart. (Rubiacaeae) colleters

Colleters are secretory structure present on many families including Rubiaceae. Particular characteristics have been described about colleters secretory cells, however senescence process are still under debate. Tocoyena bullata (Vell.) Mart. (Rubiaceae) shoot apex were collected at Jardim Botânico do Rio de Janeiro, RJ/Brazil. Stipules were separated and fragments were fixed in 2.5% glutaraldehyde and 4.0% formaldehyde in 0.05 m sodium cacodylate buffer, pH 7.2, post fixed in 1.0% osmium tetroxide in the same buffer, dehydrated in acetone, critical‐point‐drying, sputtered coated and observed. For light microscopy fragments were fixed and dehydrated, infiltrated with historesin and stained with 1% toluidine blue. For transmission electron microscopy, the samples were infiltrated with Epoxi resin. Colleters are present on stipule adaxial surface. On the beginning of development, these structures are recognized as small projections. Later on, colleters differentiated and secrete by cuticle rupture. The colleters senescence occurs in a concomitant and indissoluble way of programmed cell death. Ultrastructural analyses during the process strongly suggest the senescence is based on a non‐autolitic programmed cell death. T. bullata colleters, present at stipule abaxial surface are cylindrical secretory structures. Colleters secretory cells originated as stipule projections; differentiate; secrete and senesce by programmed cell death. The secretion and the cell dead occurs in a concomitantly and indissoluble way.     

New species of Ficus (Moraceae) from Brazil

Eight new species from Brazil,Ficus acreana,F. bahiensis, F. duartei, F. duckeana, F. hatschbachii, F. lagoensis, F. laureola, andF. rupicola, are described and illustrated. The new species are compared with other species of the genus.     

Length–weight relationship for seven freshwater fish species from Brazil

The present study reports length‐weight relationships for seven native freshwater fish species (Triportheus angulatus, Psectrogaster rhomboides, Prochilodus brevis, Leporinus piau, Cichlasoma orientale, Crenicichla menezesi, and Pimelodella gracilis) captured in a semiarid Brazilian reservoir located in the state of Rio Grande do Norte.     

Three new species of Croton (Euphorbiaceae) from Brazil

Summary   Croton imbricatus L. R. Lima & Pirani from Bahia, C. muellerianus L. R. Lima from Paraná and C. pygmaeus L. R. Lima from Rio Grande do Sul are described and illustrated. They are included in Croton section Lamprocroton (Müll. Arg.) Pax because they are much branched subshrubs or shrubs, bearing leaves with a lepidote indumentum (at least in part), inflorescences lacking bisexual cymules, and pistillate flowers with bifid styles.

---

Résumé   Croton imbricatus L. R. Lima & Pirani da Bahia, C. muellerianus L. R. Lima do Paraná e C. pygmaeus L. R. Lima do Rio Grande do Sul s?o descritas e ilustradas. Elas s?o representantes de Croton section Lamprocroton (Müll. Arg.) Pax e tal posicionamento sistemático é devido ao hábito arbustivo ou subarbustivo bastante ramificado, com indumento da folhagem lepidoto pelo menos em parte, inflorescências sem címulas bissexuadas e flores pistiladas com estiletes uma vez bífidos.

     

A new species of Microlicia (Melastomataceae) from Brazil

A new species of the genusMicrolicia,M. flava, from the highland “campo rupestre” vegetation of Serra da Canastra National Park, São Roque de Minas, Minas Gerais, Brazil, is described and illustrated.     

Flavonoid glycosides from Egyptian species of the tribe Asclepiadeae (Apocynaceae,subfamily Asclepiadoideae)

The flavonoids of 11 Egyptian species of the tribe Asclepiadeae (Apocynaceae, subfamily Asclepiadoideae) were studied: Pentatropis nivalis, Pleurostelma schimperi (subtribe Astephaninae), Glossonema boveanum, Solenostemma arghel (subtribe Glossonematinae), Cynanchum acutum, Oxystelma esculentum (subtribe Metastelmatinae), Calotropis procera, Gomphocarpus fruticosus, Gomphocarpus sinaicus, Pergularia tomentosa and Pergularia daemia (subtribe Asclepiadinae). These 11 species were found to produce flavonol glycosides. In addition, flavonol sulphates and disulphates were found in a specimen of P. nivalis. The flavonoids may provide useful taxonomic characters at several levels of classification.