Trichostomum funale Schwägrichen
Plants growing in dense, usually spherical cushions, breaking up readily, falling apart into clusters and rope-like (spirally twisted leaves) single shoots, greyish-green. Stems 2--5 cm, central strand present. Stem leaves usually spirally arranged when dry, patent when moist, lanceolate, 0.5--1.5 × 0.2--0.5 mm, appressed, of ± uniform length throughout stem, keeled, margin plane or recurved on one side, in female plants awns long and denticulate, in male plants very short to absent, costa weak below, projecting on dorsal side, margins plane or recurved on one side; distal laminal cells 2-stratose; medial laminal cells short-rectangular, extremely sinuose, thick-walled; basal juxtacostal laminal cells linear, ± sinuose, thick-walled; basal marginal proximal laminal cells short-rectangular, hyaline. Gemmae absent. Sexual condition dioicous. Seta arcuate, 1.5--2 mm. Capsule occasionally present, exserted, yellowish-green, obloid, weakly striate, concealed in awns, exothecial cells thin-walled, annulus present, operculum conical to rostellate, annulus present, peristome teeth orange, split distally, papillose. Calyptra mitrate.
Damp acidic rock; 500--2000 m; Nunavut, Ont.; La., Mich.; Eurasia.
Grimmia funalis is frequently misidentified because it is extremely variable in height, color and length of the awns. In optimal conditions, it forms extremely dense, greyish-green cushions that break up easily, falling apart into clusters and straight single plants. A distinct feature is the string-like appearance of the dried up shoots, formed by the leaves, which spirally twist round the stem. However, H. C. Greven has also seen populations without such spirally twisted leaves. Under the microscope, the mid leaf areolation with yellowish, short-rectangular, very thick and sinuose cell walls is characteristic. Grimmia calvescens, G. imberbis and G. ryanii are actually male plants of G. funalis. They grow in separate cushions with muticous to short-awned leaves, deviating greatly from the much taller, long-awned female plants. These male plants might be confused with G. elongata, which frequently grows in the same habitat, or with G. caespiticia. However, in G. elongata the basal cells are elongate, pellucid, straight and thin-walled or only slightly incrassate. In G. caespiticia the basal areolation is of shorter cells tending to be quadrate to short-rectangular, and the apex is cucullate.