General and peculiar features of vascular organization and development in shoots of Bougainvillaea glabra Choisy (Nyctaginaceae)

In the present study developmental relations between peripheral meristematic cylinder and vascular bundles of the young parts of the shoots and the relations between these bundles from the young elongating parts and those formed during secondary thickening has been elucidated. The suggestion is advanced that the limited lateral extension of bundles is an important developmental feature of the vascular system of Bougainvillaea glabra Choisy. The organization of the vascular system in thick fast growing sprouts and in the thin slow growing lateral shoots are described. It is shown that the quantitative differences in vascular organization, between both types of shoots are the manifestation of a close morphological harmonistation of the entire shoot, and particularly of its entire vascular system