Leaves with distal lamina smooth; awn smooth or sharply serrulate; lamellae 10--12 cells in height, not lobed, sometimes bearing filaments. Capsules stegocarpous (or stegocarpous but bursting irregularly), immersed to emergent, short-ovoid, annulus present, operculum cells in straight rows; eperistomate. Calyptra cucullate or rarely mitrate.

Varieties 2 (2 in the flora): North Temperate Zone, s South America.

This is an abundant moss in the arid West, often occurring with P . ovatum . In some specimens, the perigoniate plants appear separate, but this species and doubtless others are apparently occasionally rhizautoicous. Following the reasoning of R. T. Wareham's (1939) discussion, P . subsessile var. henrici is placed with the typical variety. The characters associated (H. A. Crum 1967) with P . californicum are poor: the spores are finely papillose, the leaf cells do have weak collenchymatous thickenings, and the calyptra is long-mitrate.

Lower Taxa

• Pterygoneurum subsessile var. kieneri H. Habeeb
• Pterygoneurum subsessile var. subsessile