XVI International Botanical Congess

The wood anatomy of 42 genera of Apiales and related taxa was examined for diversity patterns of systematic significance. The most Araliaceae and the woody Apiaceae share thin-walled septate libriform fibres, and scanty paratracheal axial parenchyma, they show clear trends of other wood characters. No intermediate groups between two families have been distinguished on the basis of their wood anatomy. Five general of the Araliaceae (Myodocarpus, Delarbrea, Pseudosciadium, Apiopetalum, Mackinlaya), which resemble certain representatives of Apiaceae in some features of their macromorphology, may occupy a somewhat isolated position within Apiales, as it suggested by occurrence of apotracheal (diffuse and/or diffuse-in-aggregates) axial parenchyma in those. The wood anatomical data are consistent with a hypothesis (confirmed also by the results of recent analysis of DNA sequences (Chase et al. 1993, Plunkett 1994, Plunkett et al. 1996, 1997) that Apiales is a sister group of Pittosporaceae and a number of enigmatic southern-hemisphere genera (Griselinia, Toricellia, and Aralidium), and refute the traditional concept that Apiales is closely related to Cornales.