Traits of stem anatomy of some herbaceous members of the family Polygonaceae Juss.

The stem anatomy of the vine Fallopia convolvulus (L.) Á. Löve and that of the self-supporting plant Polygonum patulum M. Bieb. is described. Two groups of tracheary system—few wide elements and many narrow ones—are present in the xylem of the herbaceous vine. The maximum vessel diameters are far greater in Fallopia convolvulus than in Polygonum patulum. Such traits are typical of woody lianas and their self-supporting relatives. The cambium can give rise to wide vessels inward of separate phloem strands in Fallopia convolvulus. The newly formed vessels may substitute for the injured ones. This favors xylem recovery from a drought-induced embolism.