Stem Anatomical Descriptors of Four Sesbania Scop. Species And Their Systematic Implication

Stem anatomical features of four Sesbania Scop. species viz. S. bispinosa (Jacq.) W. Wight, S. cannabina (Retz.) Poir., S. sesban (L.) Merr., and S. rostrata Bremek. & Oberm., were examined to add some insights for identification of these species using quantitative anatomical descriptors. Sesbania stem is composed of epidermis, cortex, vascular tissues – phloem, cambium zone and xylem, and pith, which exhibit significant variations among the species in terms of their area and thickness. Sesbania sesban showed the largest area and widest epidermal cells. The close relationship between S. bispinosa and S. rostrata was found in the stem anatomical descriptors. Moreover, S. rostrata and S. cannabina were closer to some extent according to some anatomical descriptors; also rationalizing the external morphological similarities of these species. A dichotomous key of the studied Sesbania species was made. Dendrograms based on Agglomerative Hierarchical Cluster analysis of stem anatomical descriptors also confirmed close relationships identified in previous phylogenetic analyses. Bangladesh J. Plant Taxon. 28(2): 441-449, 2021 (December)

Pollen morphology and its systematic implication on some species of Artemisia L. from Gilgit-Baltistan Pakistan

This study was accomplished to scrutinize the pollen morphology of 15 species of the genus Artemisia of the family Asteraceae from Gilgit-Baltistan region of Pakistan by means of scanning electron microscopy (SEM). Results revealed pollen grains of Artemisia species with tricolporate shape, and characterized by globular symmetry (ellipsoid ball shaped from equatorial side and three lobed rounds from polar view) with few exceptions. Additionally, the pollens are marked with reduced spinules on their surfaces which are diagnostic character for the genus Artemisia. In this study, seven micromorphological characters of pollen grains of 15 Artemisia species viz. shape of pollen, arrangement of spinules, exine sculpture, spinules base, equatorial width and polar length, were employed to construct a dendrogram following the consequential cluster analyses. In the dentrogram, four groups within the studied Artemisia species have been recognized. The pollen morphology of Artemisia could be a good taxonomic marker to cope with its taxonomic delimitations in combination with other floral and molecular attributes.

Stem anatomy and its systematic implication in Bufonia (Caryophyllaceae, Sagineae) and related genera

Stem anatomy of Bufonia and nine allied genera was studied in order to investigate the systematic value of anatomical characters in generic delimitation. Cross-sections of stems of 31 accessions representing 14 species and 3 subspecies of Bufonia, and 17 additional species of the genera Arenaria, Cerastium, Eremogone, Minuartia, Minuartiella, Odontostemma, Sabulina, Sagina, and Shivparvatia were examined using light microscopy. The characteristic features of stem anatomy in Bufonia are: 1) presence of one to four layers of parenchyma in cortex, 2) calcium oxalate crystals mostly in the endodermis, 3) presence of inner and outer sclerenchymatous pericycle, and 4) a large central pith rupturing in a linear to boat-shape mode and forming a central continuous slit. Characters such as arrangement and continuity of xylem along with the number, and arrangement of different tissues (or layers) discriminate Bufonia from the other studied genera. Stem anatomy of Eremogone, Minuartia, and Bufonia showed some degree of similarity reflecting a level of convergence in the stem anatomy that might explain the taxonomic confusion associated with this group. The present study supports previous exclusion of Bufonia koelzii and B. caespitosa from Bufonia and their inclusion in Eremogone.

Pollen morphology and numerical analysis of Tamarix L. (Tamaricaceae) in Egypt and its systematic implication

A palynological and multivariate study of six species of Tamarix L. distributed in Egypt was carried out. Pollen morphology was examined by Light Microscope (LM) and Scanning Electron Microscope (SEM). The systematic study of these species was conducted by means of numerical analysis using UPGMA clustering and PCO analysis based on 33 morphological characters, including life form, vegetative parts, fruits, floral characters, seeds and pollen grains. Pollen grains were found to be monads, radially symmetrical, isopolar, small-sized and homocolpate. Tamarix nilotica can be easily separated from other taxa by its subprolate pollen shape. Two major clades were identified by multivariate analysis of morphological characters; one of them included three species, namely T. amplexicaulis, T. passerinoides and T. macrocarpa. Our results indicate that there is a wide range of morphological similarity among the species of section Polyadenia. The other clade included T. aphylla, T. tetragyna and T. nilotica from section Tamarix and section Oligadenia.Keywords: Tamarix; Pollen Morphology; Numerical Taxonomy; UPGMA Cluster; PCO, Egypt.Bangladesh J. Plant Taxon. 24(1): 91–105, 2017 (June)