Pseudoleskea radicosa
Cat. Canad. Pl., Musci, 181. 1892.
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 homogeneous, short-rhomboidal, elliptic, or fusiform, to 40 µm, 2–3(–4):1, pellucid to opaque, prorate to near base, lumina larger than 10 µm, walls thin or rarely firm, not pitted; apical cells 2–3:1; 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, 1 or 2, sometimes reduced. Spores 16–22 µm.
Distribution
North America, Eurasia, Atlantic Islands (Iceland).
Discussion
Varieties 3 (3 in the flora).
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.
Selected References
None.
Lower Taxa
Key
| 1 | Plants large; stem apices hooked; branches few or absent; leaves 1.6-2.3 mm, strongly falcate-secund, pluriplicate; apices long-acuminate. | Pseudoleskea radicosa var. denudata |
| 1 | Plants small to medium-sized; stem apices not distinctly hooked; branches many; leaves usually less than 1.6 mm, straight, falcate, or falcate-secund, 2-plicate; apices predominantly short-acuminate to acute | > 2 |
| 2 | Plants medium-sized; leaves weakly to moderately concave, not incurved, 1.2-1.7 mm; apices usually long-acuminate; medial laminal cells opaque. | Pseudoleskea radicosa var. radicosa |
| 2 | Plants small; leaves strongly concave, often incurved, 0.8-1.3 mm; apices acute to short-acuminate; medial laminal cells pellucid. | Pseudoleskea radicosa var. compacta |