The Vascular Anatomy of the Barley Spikelet

In the spikelet axis of Proctor spring barley there was a coreof vascular tissue in which the normal collateral bundle structurewas not distinguishable. From this tissue the vascular strandsbranched 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 ovaryin four bundles of which the adaxial bundle passing close tothe ovule was the biggest. The arrangement of the vascular strandsand the presence of transfer cells indicated that assimilate,particularly from the lemma, can be easily translocated to thegrowing grain. In the collar region the spikelets, which inthe 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 maybe important in the process of translocation and grain growth.