Pterygoneurum subsessile var. kieneri
Rhodora 51: 128. 1949,.
Capsule facultatively cleistocarpous: annulus differentiated but operculum remains attached, spores released through ruptured capsule walls.
Phenology: Capsules mature Jul.
Habitat: Grassland soil
Elevation: moderate elevations (950 m)
Variety kieneri has possibly hybrid sporophytes. Two forms with identical gametophytes were present in the type collection, one with typical sporophyte, the other with that of the variety. The operculum is not dehiscent and the capsule bursts irregularly. The sporophyte apparently falls as a unit, breaking off at the base of the seta. The single collection is from Nebraska, Chase County, 12.5 km west of Champion, W. Kiener 10627 (MO).
"um" is not declared as a valid unit of measurement for this property.