EMBRYOLOGY AND CIRCUMSCRIPTION OF CAMPANULACEAE AND CAMPANULALES - A REVIEW OF LITERATURE

Embryological studies of Campanulaceae and related families were revie wed to add to discussion of appropriate circumscription of Campanulace ae and Campanulales. Embryological features very uniform Campanulaceae sens. lat. (Campanuloideae and Lobelioideae), and provide no evidence for the separation of Lobelioideae as a distinct family. Campanulacea e sens. lat. share with several other families traditionally included in Campanulales (or Asterales) a few derived embryological features (i .e., unitegmic and tenuinucellate ovules, an endothelium, ab initio Ce llular type endosperm, and an endosperm haustorium). However, an exten sive comparison with families in an expanded Asteridae shows that thos e derived embryological features are symplesiomorphies, rather than sy napomorphies indicative of close relationships among them. Combined wi th other morphological (inferior ovary), chemical (presence of inulin) , and molecular (rbcL gene nucleotide sequence) characters, embryologi cal features rather support a broad circumscription of Campanulales (o r Asterales) including Pentaphragmataceae, Stylidiaceae, Campanulaceae sens. let., Donatiaceae, Menyanthaceae, Calyceraceae, Goodeniaceae, a nd Asteraceae. Within Campanulales sens. fat. (or Asterales sens. lat. ), Menyanthaceae, Calyceraceae, Goodeniaceae, and Asteraceae are obvio usly closely related to one another. To understand more exact relation ships within the order, embryological studies are needed on Brunonia, Cyphia, Cyphocarpus, Nemacladus, Corokia, Abrophyllum, Argophyllaceae, and Alseousmiaceae.