Anomalous Secondary Growth in the Axis of Lophopyxis pentaptera (K. SCHUM.) ENGLER

1) In the axis of Lophopyxis pentaptera (K. SCHUM) ENGLER, a member of the Icacinaceae, anomalous thickening growth commences with the formation of the interrupted xylem-mass. The furrows (phloemwedges) of the interrupted xylem-mass are five in number and alternate with the orthostichies of the leaves and no more furrows are formed secondarily.2) At a later stage new strips of cambium arise on the outside of the phloem-wedges and are connected with the cambial strips lying outside the projections of the xylem, so that the ring of cambium becomes continuous. The activity of the cambium results in enclosing the phloem-wedges within the xylem, namely in the formation of the so-called pierced xylem-mass.3) At the next stage the ring of cambium ceases to divide, and successive development of the secondary rings begins to occur. And, in a thickened axis we will find several secondary rings of xylem and phloem around the pierced xylem-mass.