Hypnum circinale
Hypnum lindbergii
coiled-leaf claw-moss, coiled-leaf moss, hypnum moss
Lindberg's claw-moss, Lindberg's hypnum moss
leaves falcate-secund to circinate, ovate- to triangular-lanceolate, gradually narrowed to apex, 1.5–2.2 × 0.5–0.7 mm;
base slightly decurrent, often asymmetric with one side somewhat to strongly auriculate;
margins plane, rarely slightly recurved on one side, serrulate;
acumen long-attenuate;
costa indistinct;
alar cells few, subquadrate to rounded-triangular, region fairly well defined, 2–5 cells in marginal row;
basal laminal cells broader than medial cells, golden yellow, walls porose;
medial cells 60–80(–100) × 4–5 µm. Branch leaves 1.1–1.5 × 0.3–0.4 mm;
margins more strongly serrulate.
1–5 cm, reddish brown to yellowish green, brown with age, suberect to creeping, irregularly to sparsely branched to somewhat pinnate, branches 0.2–2 cm;
hyalodermis present, central strand well developed;
pseudoparaphyllia foliose.
falcate-secund (sometimes weakly so), oblong-ovate, not or slightly rounded to insertion, tapering gradually to apex, 0.5–2 × 0.5–1 mm;
base decurrent;
margins plane, entire to bluntly serrate especially in apex;
acumen slender or broad;
costa double, short;
alar cells abruptly enlarged, region well defined, in 2–4 rows along margins, outermost cell walls thinner;
basal laminal cells wider, shorter than medial cells, yellowish, walls porose;
medial cells 60–100 × 5–6 µm. Sexual condition dioicous;
inner perichaetial leaves oblong-lanceolate, margins serrulate at apex, apex attenuate, costa obscure.
reddish, 0.6–1.5(–2) cm.
reddish, 2.5–4 cm.
dioicous or phyllodioicous;
inner perichaetial leaves oblong-lanceolate, margins serrulate distally, apex slender.
oblique to horizontal, reddish, ovoid to ovoid-oblong, 0.8–1.5 × 0.5–0.7 mm;
annulus 1- or 2-seriate;
operculum conic-apiculate;
endostome cilia 1 or 2.
inclined, pale brown, cylindric, 2–3 mm;
annulus 2- or 3-seriate;
operculum conic-convex;
endostome cilia 2–4.
Hypnum circinale
Hypnum lindbergii
Hypnum circinale is easily identified by the often asymmetric stem leaves bearing a long-attenuate serrulate point, with one side auriculate with usually pigmented alar cells, and the small sporangia that mature in January or February and produce sporophytes between September and December. Its closest affinities are with the east Asian H. tristoviride (Brotherus) Paris, which it strongly resembles in vegetative characters. In eastern North America, H. andoi resembles some forms of H. circinale in size and appearance, but the leaf bases, especially the nature of the alar cells and auriculation in H. circinale (absent in H. andoi) are reliable distinguishing features. The plants tend to be larger on humid logs than on tree trunks and rock and are closely affixed to the substrate by rhizoids; the pseudoparaphyllia are usually terminated by an elongate cell or 1-seriate tip of 2–4 cells; and the laminal cell walls are porose. When dioicous, the antheridial plants are similar to the archegonial; when phyllodioicous, the dwarf males are epiphytic on archegonial plants.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Hypnum lindbergii is a species largely of temperate climates, most frequent in boreal and warm temperate regions, less frequent in the Arctic, occurring from sea level to alpine elevations; sporophytes are infrequently produced in spring and summer. Plants of H. lindbergii have few or no rhizoids; the supra-alar cells are shorter than the alar cells, in 1–3 rows; the capsules are furrowed when dry; and the endostome cilia are as long as the segments. The hyalodermis cortical cells, leaves usually curved to insertion, usually well-defined alar regions of swollen thin-walled cells, and often wide acute apex of many stem leaves usually separate this species from similar taxa. Hypnum pratense resembles H. lindbergii somewhat, but H. pratense tends to be very glossy, with stem leaves often complanate, and thin-walled alar cells absent.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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