Sphaerocarpos michelii var. californicus Underwood
Archegonial plants 6--15 mm in diameter, nearly orbicular to cuneate; bright green to hyaline green, central axis 2- to multistratose, lobes 1-stratose, crispate, obovate to slightly obdeltoid, apex rounded, involucres sessile, generally 2--2.6 mm high, obpyriform, fusiform, ellipsoid to slightly clavate, contracted to the orifice, mouth very small. Antheridial plants 2--6 mm in diameter, green to nearly hyaline green, lobes cuneiform to obdeltoid, involucres 260--360 µm high, crowded over the dorsal surface, orbicular, oblong to flask-shaped. Sporangia ca. 620--700 µm. Spores permanently united in tetrads, yellowish-brown to dark-brown, 115--175 µm, granulate to areolate, areolae 5--7 across the face, lacking a median tubercle, reticulations 15--30 µm in diameter, crenulate or not.
Soils of disturbed areas and areas of seasonal flooding; Ala., Ark., Calif., Fla., Ga., Ill., Kans., Ky., La., Miss., Mo., N.C., Okla., Oreg., S.C., Tenn., Tex., Va., Wash.; South America (Uruguay); s and c Europe, n Africa; Atlantic Islands (Canary Islands); Australia.
This is the most widespread and commonest species of Sphaerocarpos. It is considered weedy because of its apparent habitat preference. Sphaerocarpos texanus has not been reported from the Intermontane region of North America, which includes Arizona, Colorado, Utah, Idaho, Wyoming, Nevada, New Mexico, Idaho, and Montana, or from the very northcentral and northeastern regions of the flora area.