Sphaeroblasts in two species of Patagonian Nothofagus (Fagaceae)

Nothofagus antarctica and N. pumilio are components of the forest in the Pa tagonian region. Trees of both species show the formation of sphaeroblasts in the trunk and branches. The present work studies the histology of these structures. Several meristematic centres are formed in them. From some of t he such centres, buds and shoots emerge. They live for one or more years, b ut usually die. A probable cause may be the lack of vascular connections wi th the central vascular cylinder of the trunk. No such junction was recogni zed in the analysed samples.