Hypnum circinale
Hypnum revolutum
coiled-leaf claw-moss, coiled-leaf moss, hypnum moss
revolute 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.
leaves straight to falcate-secund, ovate or broadly ovate-oblong, gradually narrowed to apex, 0.5–1.8 × 0.4–0.6 mm;
base not decurrent, not auriculate;
margins revolute from base to near apex, entire at apex;
apex narrowly acuminate;
costa distinct to rarely ecostate;
alar cells subquadrate, not pigmented, region not well defined, not excavate, 8–15 cells in marginal row, forming clearly defined angles, 2 or 3 larger, hyaline, rectangular cells in decurrent portion;
basal laminal cells wider than medial cells, sometimes yellowish, walls porose, pitted;
medial cells 25–40 × 4–5 µm, walls not pitted.
similar, slightly smaller.
reddish, 0.6–1.5(–2) cm.
yellowish to reddish when mature, 1–2 cm.
dioicous or phyllodioicous;
inner perichaetial leaves oblong-lanceolate, margins serrulate distally, apex slender.
dioicous;
inner perichaetial leaves oblong-lanceolate, plicate, margins almost entire distally, apex short, costa indistinct.
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 to horizontal, dull yellowish to brown, oblong-cylindric, 2–3 mm;
annulus 2 (or 3)-seriate;
operculum conic;
endostome cilia 2 or 3.
Hypnum circinale
Hypnum revolutum
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.)
Varieties 2 (2 in the flora).
Hypnum revolutum is circumpolar in the Northern Hemisphere but bipolar in distribution. The species occurs at sea level in the northern portion of its range but is most frequent at higher elevations. Strongly revolute leaf margins are found in the genus only in H. revolutum, and the areolation in combination with the alar cell differentiation usually make this species readily recognizable. Creeping plants tend to be pinnate, sometimes closely and regularly; suberect plants tend to be more loosely and irregularly branched. The longest branches are the ones most distant from the stem apex. Plants of H. revolutum have outer stem cell walls often thin and collapsed inward; the stem leaves are concave. The antheridial and archegonial plants are alike.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Plants medium-sized; leaves plicate; margins strongly revolute to near apex. | var. revolutum |
1. Plants relatively small; leaves not plicate; margins plane or sometimes revolute basally. | var. ravaudii |
BC
CalFlora
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
