Taxonomic significance of leaf architecture in the genus Basella Linn. in Nigeria

Abstract

This study seeks to use the leaf architecture as a taxonomic tool for members of the genus Basella Linn. in Nigeria, namely, B. rubra Linn., B. alba Linn., B. cordifolia Lamk. and a form, B. alba round because the taxonomy of the genus Basella Linn. is not clear and there is no information on the leaf architecture of the genus. For studies of the venation pattern of the leaves, sizeable portions were taken from the standard median portion of mature leaves. Cleared leaves were stored in 50% alcohol for anatomical studies. Leaves were stained in Safranin O for 3 minutes and counterstained in Alcian blue and then were rinsed in water to remove excess stain. Stained cleared leaves were treated in serial grades of alcohol for differentiation and dehydration. Stained materials were mounted in dilute glycerol for microscopic examination. Photomicrographs were taken with the aid of 3013 ACCU-SCOPE Trinocular Microscope with Digital Camera. The areolar area was calculated from the length and breadth of the areoles measured using a micrometer inserted into the microscope eyepiece. Basella species have common generic features. Areoles are closed in B. rubra but others have veinlet endings. The area of areole is diagnostic because in B. rubra the area is 305,370±1808.91 μm2; B. alba is 501,796.75±3217.38 μm2, B. cordifolia’s area of areole is 396,394.75±2670.67 μm2 while that of B. alba round is 540,058.75±3702.28 μm2. The arrangement of druses in the areoles is also diagnostic.