THE VEGETATIVE ANATOMY OF JAUMEA CARNOSA (LESS.) GRAY (ASTERACEAE), A SALT MARSH SPECIES

Certain anatomical characters of Jaumea carnosa, a salt marsh plant, which are diagnostic, adaptive, or otherwise important for an ecological anatomy study are described. The characters which follow are noteworthy. The plant has a sympodial construction forming an extensively branched rhizome system, and erect lateral shoots which eventually become prostrate. The leaves have very few, and only moderately developed succulent characters, such as: poorly defined palisade tissue, central mesophyll cells which are slightly enlarged anticlinally, and a complete lack of sclerification in the mesophyll. A continuous schizogenous canal system lined with epithelial cells lies in the ground tissues of all stem forms and leaves. The phellem is composed of thin-walled, only lightly suberized cells. Very broad parenchymatous areas develop in the secondary tissues of the rhizome, associated with a slowing of vascular cambial activity which creates depressions in the axis. Adventitious roots arise from ground tissues close to the primary xylem and from interfasicular regions close to the primary phloem in the rhizomes.