Browsing by Subject "Morphology"

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    Morphology and taxonomy of Mondia (Apocynaceae: Periplocoideae)
    (2009) Venter, H J T; Verhoeven, R L; Bruyns, P V
    The bitypic Mondia Skeels is found in the moist tropical and subtropical forests of Africa. Both species are lianes with large leaves, fringe-like interpetiolar stipular ridges, large panicles and brownish, reddish to purplish flowers with conspicuous and well exposed gynostegia. Mondia resembles Batesanthus N.E.Br., Myriopteron Griff. and Tacazzea Decne. in being large woody climbers with large leaves, large many-flowered inflorescences, and rotate flowers with grooved translators and pollen of which the 4–6-porate grains are fused into tetrads. Mondia is distinguished from these genera by having fringe-like interpetiolar ridges and bi- or tri-segmented corona lobes. Batesanthus, furthermore, differs from Mondia by having fleshy interpetioler ridges, a corolla with recurvate tube and an annular corona. The species of Myriopteron and Tacazzea, in contrast to Mondia, have non-fleshy interpetiolar ridges, a herbaceous corolla with linear to narrowly ovate lobes, and in the case of Myriopteron keel-shaped follicles with lateral membranous fins. Apart from these three genera Mondia shows affinity to Chlorocyathus Oliv. and Stomatostemma N.E.Br. Although both genera are also large climbers, they are characterised by root tubers and flowers with campanulate corollas. Here we present descriptions of micro- and macro-morphological features of Mondia and its two species, as well as a key to the species and notes on distribution patterns, ecology and uses. We also discuss possible relationships with other genera among the Periplocoideae.
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    The void galaxy survey: photometry, structure and identity of void galaxies
    (2017) Beygu, B; Peletier, R F; Hulst, J M van der; Jarrett, T H; Kreckel, K; Weygaert, R van de; van Gorkom, J H; Aragon-Calvo, M A
    We analyse photometry from deep B-band images of 59 void galaxies in the Void Galaxy Survey (VGS), together with their near-infrared 3.6 μm and 4.5 μm Spitzer photometry. The VGS galaxies constitute a sample of void galaxies that were selected by a geometric-topological procedure from the Sloan Digital Sky Survey Data Release 7 data release, and which populate the deep interior of voids. Our void galaxies span a range of absolute B-magnitude from MB = -15.5 to -20, while at the 3.6 μm band their magnitudes range from M3.6 = -18 to -24. Their B-[3.6] colour and structural parameters indicate these are star-forming galaxies. A good reflection of the old stellar population, the near-infrared band photometry also provide a robust estimate of the stellar mass, which for the VGS galaxies we confirm to be smaller than 3 × 1010 M⊙. In terms of the structural parameters and morphology, our findings align with other studies in that our VGS galaxy sample consists mostly of small late-type galaxies. Most of them are similar to Sd-Sm galaxies, although a few are irregularly shaped galaxies. The sample even includes two early-type galaxies, one of which is an AGN. Their Sérsic indices are nearly all smaller than n = 2 in both bands and they also have small half-light radii. In all, we conclude that the principal impact of the void environment on the galaxies populating them mostly concerns their low stellar mass and small size.