Leaves of Exbucklandia populnea (Hamamelidaceae) bear a large, leathery, persistent structure at the base of their petioles which encloses the next youngest leaves produced by its shoot. By means of electron micrographs and serial sections, it was determined that the structure is formed by the appression of two lateral stipules. Such stipular morphology, but in a less elaborated form, also occurs in the infloresence region. During a vegetative flush, between one and four branches expand out from between the stipules. The origin of these branch buds within the stipular bud was studied to determine whether they arise as either collateral axillary buds or from a condensed branching system. The phyllotaxis and plastochron of leaves borne on these shoots was determined; rates of growth of these shoots during their subsequent expansion was studied and compared in relative and absolute terms. The significance of these observations for an understanding of tree architecture will be discussed.

Key words: Exbucklandia populnea, Hamamelidaceae, scanning electron microscope, shoot branching, stipules