Plants in dense to loose tufts, olive green, brownish to blackish below. Stems 1--4 cm, central strand present. Stem leaves erect and appressed when dry, recurved to squarrose when moist, broadly lanceolate, tapering to an acute apex, 1.5--2.5 × 0.4--0.6 mm, keeled, margins recurved on one or both sides, awns absent to rather long, stout and denticulate, costa firm, projecting on dorsal side, median layer of stereids present; distal laminal cells 1-stratose with 2-stratose ridges, margins 2-stratose; medial laminal cells rounded-quadrate to oblate, straight, thick-walled; basal juxtacostal laminal cells rectangular, straight, thin or slightly thick-walled; basal marginal laminal cells rectangular, thickened transverse walls. Gemmae in clusters, multicellular, occasionally present in leaf axils. Sexual condition dioicous. Seta arcuate, 3--4.5 mm. Capsule occasionally present, exserted, ovoid, brown, shiny, weakly striate, exothecial cells thin-walled, annulus present, operculum rostrate, peristome teeth orange, fully developed to irregularly cleft at apex, papillose. Calyptra mitrate.

Dry acidic to basic rock; 100--1000 m; B.C.; Calif., Oreg., Wash.; Mexico; north Africa; Eurasia; Pacific Islands (Hawaii).

Grimmia lisae is a thermophilous species with a preference for subtropical coastal areas. In North America, it occurs along the west coast, from Vancouver Island south to Mexico. From this region, it has been described frequently as a new species, see synonymy above. Grimmia lisae is closely related to G. trichophylla, differing by somewhat shorter and broader leaves that are straight and appressed when dry and recurved to squarrose when moist, and a reniform costa. Furthermore, it is characterized by a grass-green mid leaf areolation with small, rounded, frequently oblate cells with straight walls.