

Figure 1: The view looking down the axis of the stem or rachis is shown in A. A side view of the rachis is shown in B. Three clusters of flowers develop at each node of the rachis which are offset above (solid lines) and below (dashed lines). In the case of two-row barley, only the central flower at each node is fertile. As a result, one kernel would would develop at each node giving the appearance of two rows of kernels when view from above. This is the case is shown in B and is indicated by the shaded kernels in A. In the case of six-row barley, three kernels would develop at each node, thus giving the appearance of six-rows of kernels when viewed from above (Lewis and Young, 1995).