Leaves of Erythroxylum campestre, E. nanum,and E. tortuosum have been studied in different developmental stages in order to describe the leaf ontogeny and the structure of scars found in mature blades of Erythroxylum. The marginal growth of the leaves is of the "median submarginal" type. At early stages, intense activity in the adaxial meristem leads to the formation of a crest on this surface, while the laminar portion has an involuted aspect, due to the activity of the marginal meristem. The stomata develop at the same time as the mesophyll layers and the final expansion of the blade results from an intercalary growth. Blade scars were not observed during ontogeny. When present these scars appear to result from shallow injuries parallel to the midrib on the abaxial surface.
blade scar; Erythroxylaceae; Erythroxylum; foliar ontogeny
