Azolla filiculoides Lam.
Mosquito Fern Family
Pacific Mosquito Fern
Small mosslike plants with pinnately branched stems covered with minute
imbricate 2-lobed lvs. producing rootlets beneath; often reddish, 1-2.5 cm.
long, easily breaking apart; lvs. ovate, 1 mm. long, the dorsal lobe
papillate-hairy, the ventral submersed and forming sporocarps; sporocarps of 2
kinds, borne in pairs beneath the stem, the small ones ovoid and bearing 1
macrospore, the larger globose and containing masses of microspores.
Habitat: Frequent in sluggish water
at low elevs., cismontane Calif., occasional on the deserts as on Mojave R.; to
Wash., Ariz., S. Am. Bloom data not
given in Munz.
Not found in saline areas. Found below 1600 m. (Hickman, Ed. 90).
Name: Azolla, Greek name of doubtful origin. (Munz, Flora So Calif.
34). Greek, azo, to dry. Ex. Azolla,
azo+alloyo, to kill, since the plants are killed by drought. (Jaeger 32).
Latin, filum, threadlike. (Jaeger
102). New Latin, oides, a contraction of Gr. o+eidos,
denoting likeness of form, a thing that is like. (Jaeger 172). The
species name may refer to the growth pattern of small branched stems.
General: Common in the study area.
Photographed at 23rd Street. (my
comments). All too often, the characters by
which the species of Azolla are
identified are not very satisfactory; in particular, size of plant, character of
branching, overlapping of leaves, and number of microsporangia are so variable
as not to be convincing criteria for identification.
The characters used in Mason's key, however, are reasonably stable.
The key shows two species, with differences being in whether
microsporangic massulae are septate or nonseptate.
(Mason 31). Six species in the genus.
(Munz, Flora So. Calif. 35).
The 1993 Jepson Manual changes the family name from Salviniaceae
Ref: Abrams, Vol. I 35; Hickman,
Ed. 90; Mason 34; Munz, Flora So. Calif.
34; Roberts 5.
Ref: Aug 1 86 # 20.
Ref: Plant Data 296.
by F. Roberts.
Last edit 6/29/00.