Les cellules de transfert des axes sporophytiques d'Equisetum arvense: ultrastructure et histoenzymologie

Summary Transfer cells occur within vascular bundles of vegetative axes (rhizome and stem) of Equi setum arvense. They are particularly well developed in the inner side of the phloem bundle, touchinl. the carinal lacuna, where their wall-ingrowths show a polarised arrangement. Other, apparentlg less specialized transfer cells occur in the phloem bundle which have smaller ingrowths onaly faces. The histoenzymological results (phosphatase, succinate dehydrogenase and peroxidase activities) are well in accordance with the possibility of an efficient lateral transport of solutes between sieve elements (symplastic system) and carinal lacuna (apoplastic system).