Pterygoneurum subsessile

(Bridel) Juratzka

Laubm.-Fl. Oesterr.-Ung., 96. 1882,.

Basionym: Gymnostomum subsessile Bridel Muscol. Recent., suppl. 1: 35. 1806
Treatment appears in FNA Volume 27. Treatment on page 608. Mentioned on page 607, 609.

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

Distribution

V27 879-distribution-map.gif

North Temperate Zone, s South America.

Discussion

Varieties 2 (2 in the flora).

Pterygoneurum subsessile 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 (1939), var. henrici is placed with the typical variety. The characters associated with P. californicum (H. A. Crum 1967) are poor: the spores are finely papillose, the leaf cells do have weak collenchymatous thickenings, and the calyptra is long-mitrate.

Selected References

None.

Key

1 Capsule dehiscent by the fallen operculum Pterygoneurum subsessile var. subsessile
1 Capsule bursting irregularly, annulus differentiated but not fissile Pterygoneurum subsessile var. kieneri