4. Pylaisia intricata (Hedwig) Schimper in P. Bruch and W. P. Schimper, Bryol. Europ. 5: 88. 1851. (as Pylaisaea).
Pterigynandrum intricatum Hedwig, Sp. Musc. Frond., 85, plate 18, figs. 1-5. 1801; Hypnum intricatum (Hedwig) Müller Hal.; Pterogonium intricatum (Hedwig) Schwagrichen; Pylaisia velutina Schimper; Pylaisiella intricata (Hedwig) Grout; P. velutina (Schimper) Kindberg; Stereodon intricatus (Hedwig) Lindberg & Arnell
Plants yellowish. Stems terete-foliate, irregularly pinnate, branches 5 mm, creeping or sometimes ascending and curved, subjulaceous; pseudoparaphyllia triangular to semicircular. Stem and branch leaves differentiated. Stem leaves straight or somewhat falcate, ovate-lanceolate, suddenly narrowed to apex, concave, not plicate, 0.8-1 × 0.2-0.4 mm; margins plane; acumen short; costa double, short; alar cells 6-12 along margins, in 6-9 rows; medial laminal cells 30-65 × 5-6 µm. Branch leaves oblong-lanceolate, larger, 1.1-1.2 × 0.3-0.4 mm. Seta 2-2.4 cm. Capsule erect to suberect, oblong-cylindric, 1.8-2 × 0.6-0.7 mm; exothecial cell shape variable; operculum rostrate, obliquely long-pointed; peristome reduced; exostome teeth lanceolate, 0.2 mm, base 50 µm wide, finely papillose distally; endostome adherent to exostome teeth, basal membrane well developed, segments 2-fid, split, internal surface roughly and finely papillose, segment and cilia connate. Spores 16-32 µm.
Capsules mature late summer-early fall. Trunks of broad-leaved trees; moderate to high elevations; Alta., B.C., Man., N.B., N.W.T., N.S., Ont., Que.; Ala., Ariz., Colo., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Maine, Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va., Wis.
Pylaisia intricata is a rare species endemic to the flora area. The leaves are homomallous and erect-spreading when dry, wide-spreading when moist, and cordate at the base; the distalmost annulus cells are vesiculose and deciduous. The species is characterized by rather small branch leaves, long-pointed opercula, finely papillose external surface of the distal portion of exostome teeth, and adherent endostome; it can be distinguished from P. polyantha by its adherent endostome and larger spores.