A STUDY OF THE ORIGIN OF THE STOLON AND EXPANSION OF THE CORM OF SAGITTARIA SAGITTIFOLIA L.

The stolon arises at the second or third leaf axil from the apex. During development of a stolon, cell divisions occurred orderly alongthe basal and lateral limits of the incipient stolon primordium, forming a zone of parallel curving layers referred to as the shell zone. The stolon primordium appears to be associated with an active outward growth by the shell zone.The tunica of the stolon apex is uaually one layered. Thickening and elongation of stolon are manifested mainly by expansion and axil elongation of the cells.In the process of corm formation, figures of mitotic nuclear divisions appear in the cells of the ground tissue at several nodes of the stolon near its apex and cell expansion occurs afterwards. Simple starch grains are stored in the corm in general, but both simple and compound starch grains are formed in the stolon.