Monographs Details: Azolla
Authority: Proctor, George R. 1989. Ferns of Puerto Rico and the Virgin Islands. Mem. New York Bot. Gard. 53: 1-389.
Scientific Name:Azolla

Type Species. Azolla filiculoides Lamarck, ranging from Califomia to Chile.

With characters ofthe family. Chromosome number: n = 22.M/P>

A widespread genus of ten living species, no table for the symbiotic cyanobacteria inhabiting the frond-cavities, and for having among the most complex reproductive structures of any plant.

Because of its nitrogen-fixing properties, Azolla has been cultivated for many years as a green manure in the rice fields of southeastem Asia. The generic name is derived from the Greek azo, to dry + olluo, to kill, presumably because this aquatic fem is killed by drying.

Special Literature. Svenson, H. K. 1944. The New World species of Azolla. Amer. Fem J. 34: 69-84; Lumpkin, T. A. i& D. L. Plucknett. 1980. Azolla: Botany, physiology, and use as a green manure. Econ. Bot. 34: 111-153; Tryon, R. M . & A. F. Tryon. 1982. Ferns and allied plants, pp. 776-781,13 figs.; Perkins, S. K., G. A. Peters, T. A. Lumpkin & H. E. Calvert. 1985. Scanning electron microscopy of perine architecture as a taxonomic tool in the genus Azolla Lamarck. Scanning Electr. Micr. 1985/IV: 1719-1734, 30 figs.