Comparative Foliar and Petiole Anatomy of Some Members of the Genus Dieffenbachia Schott in the Family Araceae

This study provides detailed information of the anatomical attributes of the epidermis and the three regions of the petiole of four members of the genus Dieffenbachia Schott. Fresh samples of the leaves of Dieffenbachia picta Schott, Dieffenbachia oerstedii Schott, Dieffenbachia senguine (Jacq) Schott and Dieffenbachia senguine cultivar ‘Candida’ Schott were used. Epidermal peels and transverse sections were made following standard procedures. Generic characters revealed uniform epidermal cell shape on the abaxial surface, wavy to undulating and straight to wavy anticlinal wall patterns on the adaxial and abaxial surfaces respectively, brachyparacytic stomata types, round abaxial petiole outline, the presence of raphides and druses in the petioles of all the taxa. Delimiting features include irregular epidermal cell shape on the adaxial surfaces of D. senguine and D. senguine cv. ‘Candida’, additional anomocytic stomata types on the abaxial surfaces of D. picta, D. oerstedii and adaxial surface of D. senguine, cuticular striations on the abaxial surfaces of D. oerstedii and D. senguine cv. ‘Candida’, druses and raphide bundle on the epidermal surface of D. senguine only, flat adaxial petiole outline and slightly concave adaxial petiole outline in the proximal and median regions of D. senguine cv. ‘Candida’ and the presence of lamellar collenchyma cells in the petiole of D. picta. Data for both quantitative and qualitative characters were subjected to Principal Components Analysis and Single Linkage Cluster Analysis. Interestingly, anomocytic stomata complex, cuticular striations, raphide bundles and druses and the adaxial petiole outline separated D. senguine and D. senguine cv. ‘Candida’.