Fig. 3.3-4. Transverse section of rush (Juncus). Like the stems of Scirpus (Fig. 3.3-3) this one of Juncus is light-weight due to having intercellular air spaces, but in Juncus they are very large spaces, and in fact as much as half the volume of the stem is just air space, not cellular material. Notice all the debris in the intercellular spaces – those are remnants of cells destroyed as neighboring cells were pulled apart. The top of the micrograph shows vascular tissues, and the white spaces arranged in circles are xylem vessels. The red band between the outer aerenchymatous cortex and the vascular tissues is the endodermis (pages 151-152 and 275-278 in Plant Anatomy (Mauseth)).