Hypnum radicosum Mitten, J. Linn. Soc., Bot. 8: 31. 1864; Lescuraea radicosa (Mitten) Mönkemeyer

Plants medium-sized to large, in thick mats, green, yellow-green, or orange-green. Stems with branches robust, julaceous, apices usually curving up; central strand present; paraphyllia many, filamentous to foliose, branched. Leaves appressed to somewhat erect when dry, erect-spreading when moist, glossy or dull, ovate to ovate-lanceolate, asymmetric, usually falcate to falcate-secund, 0.6-2(-2.4) mm; margins narrowly recurved to mid leaf or to near acumen; apex abruptly acute to short- or long-acuminate, hair-point absent; costa subpercurrent to percurrent, yellow-green, sometimes sinuate; alar cells transversely elongate to quadrate, region small to medium-sized; medial laminal cells , short-rhomboidal, elliptic, or fusiform, to 40 µm, 2-3(-4):1, pellucid to opaque, prorate to near base, , walls thin or rarely firm, not pitted; ; juxtacostal cells somewhat shorter than more distal cells, walls not pitted. Capsule erect to suberect, symmetric, 1-2 mm; endostome basal membrane 1/4 -1/3 exostome length, segments shorter than exostome, cilia usually present, or 2, sometimes reduced. Spores 16-22 µm.

Varieties 3 (3 in the flora): North America, Eurasia, Atlantic Islands (Iceland).

Pseudoleskea radicosa is a common and variable species found at moderate to high elevations; the capsules mature in summer. Two of the three varieties are quite distinctive. Pseudoleskea radicosa is closely related to P. incurvata but differs in the longer, more homogeneous, thin-walled, and wider laminal cells. Combined ecological, molecular and morphological studies of the varieties are needed to determine their distinctiveness.