Procambial and cambial variants in Serjania and Urvillea species (Sapindaceae: Paullinieae)

Abstract

For the purpose of comparing the structure of vascular cylinders, and procambial and cambial variants of Serjania Miller and Urvillea Kunth species, we studied the stems of five species, in order to add to the structural knowledge of these genera belonging to the widely distributed Sapindaceae family. Stems of sampled species were collected at Estação Ecológica do Caiuá, Diamante do Norte (PR), Brazil; and were analyzed using traditional anatomical techniques. We analyzed five species of two genera from the Paullinieae t ribe: three species of Serjania (S. communis, S. fuscifolia, and S. meridionalis) and two of Urvillea (U. leavis and U. ulmacea); in which we describe the primary and secondary growths, the number of peripheral cylinders, the type of cylinders concerning its origin, the type of stem, and the origin of the cambial or tissue variant. Serjania stems exhibit the compound and corded types, while the cleft and mixed (cleft/corded) types have been recorded in Urvillea species. All species have peripheral vascular cylinders in which the stems of S. communis and S. fuscifolia form the procambial and cambial var iant s dur ing primary g rowth, whereas the stem s of S. meridionalis, U. leavis, and U. ulmacea develop the cambial variants during secondary growth.