Fig. 27.—Transverse section of the stem of Eriochloa polystachya. × 25
In the stem of Eriochloa polystachya, all the vascular bundles are more or less peripheral in position leaving a wide area of parenchymatous cells in the centre. The outline of the stem in cross section is rotund or ovate-rotund with the front side somewhat flattened and straight. The epidermal cells alone are thickened. A well developed continuous ring of sclerenchyma is present and this is connected with the epidermal layer at short intervals by means of short sclerenchymatous bands. So the parenchymatous cells of the cortex lying outside the sclerenchymatous ring are divided into small isolated areas. There are three series of vascular bundles.
Fig. 28.—Transverse section of a portion of the stem of Eriochloa polystachya. × 70
1. Epidermis; 2. sclerenchyma; 3. vascular bundle.
One series consists of small bundles lying inside the sclerenchyma ring at the base of each of the connecting bands. The second series is made up of large vascular bundles imbedded in the ring so as to bulge out inside the ring. The vascular bundles of the third series are found just away from the ring and separated from it by a few layers of parenchymatous cells. (See figs. 27 and 28.)
Fig. 29.—Transverse section of the stem of Setaria glauca. × 15