Pilularia americana

A. Braun

Monatsber. Königl. Preuss. Akad. Wiss. Berlin 1863: 435. 1864.

Common names: American pillwort
Treatment appears in FNA Volume 2.

Plants forming dense clones. Leaves 1.6–10.2 cm, sparsely pubescent. Sporocarp stalks attached at base of leaf, 1–3 mm. Sporocarps globose, 1.6–2.7 mm diam., covered with matted hairs until mature; raphe minute, teeth lacking. Sori 4.

Phenology: Sporocarps produced spring–fall (Apr–Oct).
Habitat: In shallow water of ponds and temporary pools and on reservoir margins
Elevation: 50–600 m


V2 745-distribution-map.gif

Ala., Ark., Calif., Ga., Kans., Mo., Nebr., N.C., Okla., Oreg., S.C., Tenn., Tex., Mexico in Baja California


Pilularia americana also has been reported from Alaska. I have seen no vouchers from Alaska, nor have I seen the Oregon vouchers. Because of its grasslike appearance and subterranean sporocarps, P. americana is probably overlooked and more common than records indicate. The telltale circinate vernation of the leaves is the best characteristic for distinguishing it from similar plants.

Pilularia caroliniana A. Braun, an invalid name, has been used for this species and may appear on specimens.

Selected References


Lower Taxa

... more about "Pilularia americana"
David M. Johnson +
A. Braun +
expanded +
pea--shaped +
American pillwort +
Ala. +, Ark. +, Calif. +, Ga. +, Kans. +, Mo. +, Nebr. +, N.C. +, Okla. +, Oreg. +, S.C. +, Tenn. +, Tex. +  and Mexico in Baja California +
50–600 m +
In shallow water of ponds and temporary pools and on reservoir margins +
multicellular +
long-petioled +
terete +  and filiform +
1.6 cm16 mm <br />0.016 m <br /> (10.2 cm102 mm <br />0.102 m <br />) +
subterranean +
Sporocarps produced spring–fall (Apr–Oct). +
Monatsber. Königl. Preuss. Akad. Wiss. Berlin +
Illustrated +
0.16 cm1.6 mm <br />0.0016 m <br /> (0.27 cm2.7 mm <br />0.0027 m <br />) +
subterranean +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Pilularia americana +
Pilularia +
species +
amphibious +  and aquatic +