A secondary respiratory tissue or modified periderm, found in many aquatic plants and distinguished by the large intercellular spaces.

n. (Gr. aer, air; enchyma, an infusion) parenchyma tissue with large and abundant intercellular air spaces; air-storing tissue; resembles the tissue of cork.

Aerenchyma are parenchyma cells that are associated with an air space or surround open canals as in the air space of a monocot vascular bundle or the vallecular or carinal canal of a horsetail. DIAGRAM: Tissue Types PHOTOS