Flora of North America species comparison

Pterygoneurum ovatum is the most common species of the genus and serves to stabilize arid soils (S. Flowers 1973). The setae may reach 3 mm. Faint thickenings reminiscent of a rudimentary peristome can sometimes be found associated with spore sac remnants dug out of the operculum, and the laminal distal cells may by simply papillose abaxially as in P. lamellatum. R. T. Wareham (1939) found the characters of Pterygoneurum ovatum var. incanum Juratzka, the long awns and short setae, inconstant in both American and European material.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

The operculum of Pterygoneurum lamellatum is commonly long-conic when dry, while that of P. ovatum is generally linear. The peristome may be trellislike (illustrated by S. Flowers 1973) or a rudimentary arrangement of small plates over a membrane (R. H. Zander 1993), or even absent. Also keying to P. lamellatum is the British Columbian specimen reported by T. T. McIntosh (1989) as Tortula wilsonii (Hooker) R. H. Zander. This proved to be a species, possibly new, of Pterygoneurum distinguished by broadly recurved leaf margins and multiple papillae on both sides of the leaf above mid leaf. The adaxial costal lamellae are distinct but occasionally absent in some plants, which then phenocopy Tortula or Hilpertia. This specimen in turn proved to be similar to a Pterygoneurum discussed but not formally described by B. M. Murray (1992) for Alaska; a name will be provided in a future publication.

(Discussion copyrighted by Flora of North America; reprinted with permission.)