Fig. 5.3-11. Transverse section through water lily petiole. The hollow, round red object is a strange looking structure, almost like a crystal or piece of debris. But knowing that this is water lily leaf material, we know to expect branched astrosclereids, and that is what this is – an arm has been cut in transverse section. Although it may appear as if the arm is located within a cell, it actually is in an intercellular space. Water lily petioles have long air chambers (intercellular spaces), and astrosclereid arms often extend up and down these air chambers for a long distance. If this part of the petiole were cut into many sections, each about 10mm thick, most would have sections of this astrosclereid that look just like this, and only three or four sections would have the astrosclereid’s body.