Novelties in secretory structures and anatomy of Rhynchosia(Fabaceae)

Abstract

A comparative anatomical study was carried out on the secretory structures of leaflets from taxa belonging to the genus Rhynchosia -taxa difficult to delimit because of uncertain interspecific relations -in order to evaluate the potential diagnostic value of these anatomical traits for taxonomic assignment. A further objective was to establish consensual denomination for these secretory structures. The new anatomical features found in these taxa were sufficiently consistent to separate the species evaluated. The presence and localization of glandular-punctate structures bulbous-based trichomes, the number of layers in the palisade parenchyma and the arrangement of vascular units distinguish the taxa investigated and these characteristics can be extended to other species of Papilionoideae. The trichomes analyzed were described and classified into five types. Depicted in diagrams, photomicrographs, and by scanning electron microscopy, and listed for the first time at the genus and species levels. The information obtained served to effectively distinguish the taxa investigated among species of Papilonoideae.

Foliar anatomy of Rhynchosia spp. (Leguminosae, Papilionoideae) from Roraima state, northern Brazilian Amazon

“…Morphological types of glandular trichomes were identified following Vargas et al (2015), who recognized four types of glandular trichomes (ellipsoid capitated trichomes, spheric glandular trichomes, vesicular glands, and bulbous-based trichomes). Photomicrographs of the material were obtained with an optical Nikon Eclipse E200 microscope coupled with a Motican 10 camera, and the images were captured using the Motic Image Plus 2.0 software and measured using Image Pro Plus 2.0 software.…”

“…Foliar anatomical characters, mainly regarding the presence and type of secretory structures, may be useful characters for the delimitation of Phaseolae taxa (Melo et al 2010;Brubaker and Lersten 1995;Lackey 1978;Tourn VOL. 49(1) 2019: 28 -35 ACTA AMAZONICA et al 2009;Vargas et al 2015). Anatomical data on the Rhynchosia leaflets and petiole are available for 21 species (Solereder 1908;Metcalfe and Chalk 1950;Bhattacharyya and Marheshwari 1970;Lackey 1978;Melo et al 2010;Vargas et al 2015).…”

“…49(1) 2019: 28 -35 ACTA AMAZONICA et al 2009;Vargas et al 2015). Anatomical data on the Rhynchosia leaflets and petiole are available for 21 species (Solereder 1908;Metcalfe and Chalk 1950;Bhattacharyya and Marheshwari 1970;Lackey 1978;Melo et al 2010;Vargas et al 2015). Anatomical studies of Rhynchosia revealed a variation of glandular trichomes present on the leaflet blade in some species.…”

“…The presence, absence, and position of these glandular structures, denominated as extrafloral nectaries, were considered useful for the distinction among groups of Indian species (Bhattacharyya and Marheshwari 1970). Besides the presence and distribution of glandular trichomes, other foliar anatomical characteristics, such as the shape of the epidermal cells and vascular bundles, and sclerenchyma discontinuity in leaflet blades, were important to distinguish some Brazilian species (Vargas et al 2015). No detailed micro-morphological studies on petiole anatomy in Rhynchosia have been published.…”

Taxonomic studies of the genus Rhynchosia Lour. (Phaseoleae, Fabaceae) in South Africa: A review of section Chrysoscias

“…The vestiture is composed of both glandular and non-glandular trichomes (bulbous-based and uniseriate hairs) . The cross section of the leaf and SEM micrographs revealed that there are four types of trichomes that occur in section Chrysoscias, differentiated according to their shape (terminology adapted from Vargas et al, 2015). The four types of trichomes are:…”