Perforation plate diversity in Illicium floridanum (illiciaceae) with respect to organs, provenance, and microtechnical methods

Pit membrane remnants in scalariform perforations of mature Illicium floridanum vessels of stems and roots from three sources were studied with scanning electron microscope (SEM). Several methods of preservation and microtechnical treatment were used; results for all of these methods, for the three sources, and for the two organs revealed similar patterns. The perforation pit membranes illustrated are believed to be relatively free of artifacts. Pit membrane presence in perforations of all collections of I. floridanum studied ranges from intact non-prose pit membranes to near-absence of any pit membrane fragments. However, the extreme conditions are relatively infrequent, and the most common condition is presence of less than 50% of the pit membrane; presence of more than 50% of the pit membrane is somewhat less common. The phylogenetic significance of pit membrane presence in perforations is considered a symplesiomorphic feature for angiosperms. Presence of pit membrane remnants in perforations is valuable in phylogenetic analyses of angiosperms.