Rhizomes with 2 scales at each node. Erect stems absent. Leaves apparently attached to rhizome, 5--25 ´ 1--4 mm; blade linear-lanceolate, base cuneate, margins entire, glabrous, apex round to round-acute. Inflorescences: spathe 2-leaved, enclosing pistillate flowers. Flowers unisexual, staminate and pistillate on different plants; staminate flowers unknown; pistillate flowers sessile, ca. 5 mm. Fruits ovoid. Seeds not seen.

Flowering spring--summer. Sandy substrates of marine waters; -2--0 m; Fla.

SELECTED REFERENCE

Eiseman, N. J. and C. McMillan. 1980. A new species of seagrass, Halophila johnsonii, from the Atlantic coast of Florida. Aquatic Bot. 9: 15--19.