The Vascular Anatomy of the Barley Spikelet

Abstract

In the spikelet axis of Proctor spring barley there was a core of vascular tissue in which the normal collateral bundle structure was not distinguishable. From this tissue the vascular strands branched out, in sequence, to the sterile lateral spikelets, the glumes, the lemma, the palea, the lodicules and the stamens. The vascular tissue of the spikelet axis terminated in the ovary in four bundles of which the adaxial bundle passing close to the ovule was the biggest. The arrangement of the vascular strands and the presence of transfer cells indicated that assimilate, particularly from the lemma, can be easily translocated to the growing grain. In the collar region the spikelets, which in the mature ear bear small grains, were less well vas-cularized. In the vascular tissue beneath the ovary were thick-walled cells. These cells and the cells of the funiculus-chalaza region may be important in the process of translocation and grain growth.