The Anatomy of Contractile Roots in Eucomis L'H?rit

The anatomical changes in the different tissues during rootcontraction were studied in two species of Eucomis (Liliaceae).It is evident that the shortening of the root is brought aboutby radial and tangential broadening and longitudinal shorteningof the perivascular cortical cells. This tissue is hence calledcontractile parenchyma. As a result of this contraction thecell walls of the exodermis, endodermis, pericycle, phloem andpith become buckled longitudinally while the annular and spiralthickenings of the xylem are pressed together.