Flora of North America species comparison

2–5 cm, commonly branching by innovations, frequently dendroid.

simple or branched by subfloral innovations.

2.5–6 mm, densely imbricate and crowded toward the stem and branch tips, erect-appressed and somewhat incurved when dry, reflexed and widely spreading when moist, gradually to rather abruptly contracted to the blade, the hinge-cells sharply differentiated;

sheath ovate to obovate, hyaline-margined on the flanks, with a wedge of incrassate hinge cells at the shoulders and extending a short distance up the blade margin;

blade broadly oblong-lanceolate to narrowly linear-lanceolate, only slightly concave, toothed from apex almost to the shoulders, or sometimes subentire;

costa percurrent or slightly excurrent as a subulate, serrate to smooth point, smooth abaxially or sparingly toothed towards the tip;

lamellae 30–46, entire in profile, 4–7 cells high, the marginal cells enlarged, thick-walled and coarsely papillose, in section rounded to elliptical, broader than high, the distal wall broadly convex, the lumen rounded pentagonal;

sheath cells short-rectangular to ± isodiametric approaching the blade;

cells on abaxial surface of blade 24–27 µm, irregularly quadrate, ± isodiametric, thick-walled, the transverse walls often thicker.

with a sheathing base merging gradually or ± abruptly contracted to the blade, the sheath entire (toothed in P. contortum), with or without incrassate hinge-cells at the shoulders, not hyaline-margined (except in P. urnigerum);

margins serrate, toothed, or entire, without a differentiated border of elongated cells;

adaxial lamellae numerous and compact, occupying the full width of the blade, or somewhat fewer with an evident marginal lamina, marginal cells not differentiated, or strongly differentiated, thick-walled and coarsely papillose.

1–4 cm, typically one per perichaetium but several per plant at the tips of branches.

smooth.

dioicous;

male plants similar to females in appearance, or bud-like and inconspicuous.

2–3 mm, short-cylindric to ovate-cylindric, erect to inclined, light brown to reddish brown to blackish with age;

exothecium mammillose, densely areolate, the cells rounded quadrate, incrassate, with slit-like pits in the outer wall;

peristome 300–350 µm, divided to 0.6, the teeth rather broad, reddish brown with hyaline margins.

ovoid to short-cylindric, ± regular to somewhat asymmetric, terete, sometimes with 4 or more indistinct angles or ridges;

hypophysis not differentiated, tapering;

stomata none;

exothecium mammillose to scabrous, the exothecial cells mamillate or with a single papillate projection of the outer wall;

operculum rostrate from a convex base;

epiphragm persistent, attached to the peristome teeth;

peristome deeply reddish pigmented (at least in the median line), the teeth 32, compound, with median sinus narrow or almost obliterated.

with a densely matted felt of hairs, covering most or all of the capsule.

10–18 µm.

finely papillose.