TREATMENT FROM THE JEPSON MANUAL	previous taxon | next taxon Jepson Interchange (more information)
	©Copyright 1993 by the Regents of the University of California Print edition is available from the University of California Press

	The second edition of The Jepson Manual (2012) is available from the University of California Press
	See also the Jepson eFlora, which parallels the Second Edition

AZOLLACEAE

MOSQUITO FERN FAMILY

Alan R. Smith

Plant free-floating or stranded on mud, generally 1–5 cm, often fan-shaped; roots pendent from stem forks, unbranched
Stem forked repeatedly or pinnate, thread-like, easily fragmented at joints
Leaves alternate, in 2 rows, sessile, often overlapped, 0.5–1.5 mm, seemingly paired but actually of 2 roundish to ovate lobes; upper lobe floating or emergent, thick, greenish or reddish, margin whitish; lower lobe submersed, generally slightly larger, thinner, whitish
Sporangia in seemingly axillary cases of 2 kinds, cases generally in pairs of 1 kind
Male sporangium case 1.2–2 mm diam, spheric; tip dark-pointed; wall transparent; sporangia generally 20–100+, long-stalked; spores 32 or 64, spheric, in generally 3–6 barbed masses
Female sporangium case 0.2–0.4 mm diam, hemispheric or spheric; tip obtuse, covered by dark, conic, spongy structures that aid in flotation; wall ± opaque; sporangium 1, sessile; spore 1, spheric
Genera in family: 1 genus, ± 7 species: ± worldwide. Salvinia molesta D.S. Mitch. has been tentatively identified from Walter's Camp, Imperial Co.; more study needed.