Azolla cristata

Description

Azolla cristata has been misidentified as Azolla caroliniana in many instances. However, recent research confirms that A. caroliniana is a synonym for Azolla filiculoides. The species can be differentiated through microscopic examination of female spores (megaspores). Key distinguishing characteristics include: * Hairs on the upper side of floating leaves consist of 2 or 3 cells. * Upper lobe of floating leaf is sharply pointed with a narrow unpigmented margin. * Sprouts have a compact growth habit and lie flat on the water surface. In contrast, Azolla filiculoides exhibits: * Hairs on the upper side of floating leaves consist of a single cell. * Upper lobe of floating leaf is obtuse with a relatively wide unpigmented margin. * Sprouts grow loosely, often extending out of the water.