Contrasting phylogenetic signals and evolutionary rates in floral traits of Neotropical lianas

The diversity of floral forms has long been considered a prime example of radiation through natural selection. However, little is still known about the evolution of floral traits, a critical piece of evidence for the understanding of the processes that may have driven flower evolution. We studied the pattern of evolution of quantitative floral traits in a group of Neotropical lianas (Bignonieae, Bignoniaceae) and used a time-calibrated phylogeny as basis to: (1) test for phylogenetic signal in 16 continuous floral traits; (2) evaluate the rate of evolution in those traits; and (3) reconstruct the ancestral state of the individual traits. Variation in floral traits among extant species of Bignonieae was highly explained by their phylogenetic history. However, opposite signals were found in floral traits associated with the attraction of pollinators (calyx and corolla) and pollen transfer (androecium and gynoecium), suggesting a differential role of selection in different floral whorls. Phylogenetic independent contrasts indicate that traits evolved at different rates, whereas ancestral character state reconstructions indicate that the ancestral size of most flower traits was larger than the mean observed sizes of the same traits in extant species. The implications of these patterns for the reproductive biology of Bignonieae are discussed. (C) 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102, 378-390.

HOMOLOGIES OF FLORAL STRUCTURES IN VELLOZIACEAE WITH PARTICULAR REFERENCE TO THE CORONA

New data on floral morphology, development, and vasculature in two Brazilian genera of the monocot family Velloziaceae (Pandanales) are used to explore the homologies of their unusual floral structures, especially the corona of Barbacenia and the corona-like appendages and multiple stamens of some Vellozia species. All Velloziaceae have epigynous flowers. Some species of Vellozia are polyandrous, and stamen number can be variable within species. In Vellozia jolyi, there is a single stamen opposite each sepal and a stamen fascicle (of three secondary stamens) opposite each petal. Each stamen possesses a single vascular bundle, and these are united into a single aggregate bundle in proximal regions of the fascicle. Stamens mature centripetally within each fascicle. The coronal appendages of both genera are closely associated with the stamens, but they share some vasculature with the tepals and develop late in ontogeny. The coronal organs cannot readily be homologized with any of the typical floral organs, but they show partial homology with both tepals and stamens. They are most readily interpreted as a late elaboration of the region between the petals and stamens associated with epigyny and the hypanthium.

Apocynaceae sensun strictum from the Mucuge Municipal Park, Bahia, Brazil, including the valid publication of two names in Mandevilla Lindl.

Apocynaceae sensun strictum from the Mucuge Municipal Park, Bahia, Brazil, including the valid publication of two names in Mandevilla Lindl. The flora of Rauvolfioideae and Apocynoideae, which together form Apocynaceae s.s., from the Mucuge Municipal Park, Chapada Diamantina, State of Bahia, Brazil, is presented. Eight species and five genera were recognized. Mandevilla is the most diverse genus, With four species: M. scabra (Hoffmans. ex Roem. & Schult.) K. Schum., M. tenuifolia (J.C. Mikan) Woodson, M. bahiensis (Woodson) M.F. Sales & Kinoshita-Gouvea, and M.microphylla (Stadelm.) M.F. Sales & Kinoshita-Gouvea, the last two are a new status and a new combination, respectively, whose names are being validly published here. The four remaining genera are each represented by one species: Couma rigida Mull. Arg., Stipecoma peltigera (Stadelm.) Mull Arg,, Temnadenia violacea (Veil.) Miers, and Himatanthus bracteatus (A. DC.) Woodson. Identification key, descriptions, comments and illustrations are presented for every species.

Metal contamination in urban park soils of SA o pound Paulo

There has been little research on metal concentration levels in urban soils of SA o pound Paulo, a city with 19 million inhabitants with severe pollution problems. In the present study, the concentration of As, Ba, Cr, Cu, Pb, Sb and Zn, were determined by INAA and XRF in surface soil samples from 7 public parks located within SA o pound Paulo city. The results obtained showed that soils of SA o pound Paulo public parks present concentration levels of the studied elements higher than the reference values for soils in SA o pound Paulo State. Traffic related elements such as Cu, Pb and Zn presented high concentrations in parks located near avenues of highly dense traffic and may be associated to vehicular sources.