Abstract

• Leaf architectural characteristics of the Family Convolvulaceae in Mandalay and Pyin oo lwin area were collected and studied during the year 2016 – 2017 . According to the identification 21 species of 7 genera were recorded in study area. The resulting species were one species of Evolvulus, Jacquemontia, Operculina and Porana, two species of Argyreia, five species of Merremia and ten species of Ipomoea. The leaves samples were decolorized by Method of Mishra et al. (2010) in Department of Botany, University of Mandalay. The qualitative features and the venation pattern of cleared leaves samples were characterized. It was found that the leaves were variously observed in shape, base, apex and margin. The margins were entire or 3-lobed. The primary veins were stout or massive and predominant tertiary vein angles were Right Right (RR), Acute Obtuse (AO), Obtuse Acute (OA), Right Obtuse (RO), Acute Right (AR), Right Acute (RA), or Acute Acute (AA). The marginal ultimate venations were looped, incomplete, or fimbriate. The primary vein categories are pinnate, actinodromous basal and actinodromous suprabasal. The secondary vein categories were brochidodromous, weak brochidodromous, cladodromous, weak cladodromous and actinodromous. Stoma types were anisocytic, anomocytic and paracytic. According to the quantitative characteristics, leaf areas were found to be variously between 40 mm2 and 460 mm2. The smallest leaf area was observed in Evolvulus nummularis (L.) L. and the largest one was in Argyreia laxiflora (Prain) Prain. The number of secondary veins along one side was variously observed between 4 and 13. The angle between primary and secondary vein, number of areoles per mm2, veinlets entering areoles per mm2, and highest vein order were different among the species. According to the different qualitative and quantitative characteristics, the leaf arichitecture provides valuable data for practical identification on members of Convolvulaceae.