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opal pohlia, opal thread-moss, pohlia moss

nodding pohlia, nodding thread-moss, pohlia moss

Habit Plants medium-sized to large, green, whitish, or sometimes bluish tinged, shiny. Plants small to large, green or rarely reddish, dull.
Stems

0.5–2.5 cm.

0.5–3.5(–10) cm.

Leaves

erect to ± spreading, lanceolate to elliptic, 0.8–2 mm;

margins serrulate to serrate in distal 1/3;

costa subpercurrent;

distal medial laminal cells linear-rhomboidal, vermicular, firm, 70–140 µm, walls thin.

erect to ± spreading, lanceolate to ovate-lanceolate, 2 mm;

base not or scarcely decurrent;

margins subentire or more often serrulate to serrate in distal 1/3;

costa subpercurrent, percurrent, or rarely short-excurrent;

distal medial laminal cells hexagonal to rhomboidal, firm, 50–90 µm, walls moderately thick.

Seta

orange to orange-brown.

orange to orange-brown.

Sexual condition

paroicous, rarely dioicous;

perigonial leaves in dioicous plants linear- or long-lanceolate from ovate base;

perichaetial leaves strongly or rarely weakly differentiated, linear-lanceolate.

paroicous, rarely dioicous;

perigonial leaves ovate-lanceolate;

perichaetial leaves somewhat differentiated, ± long-lanceolate.

Capsule

inclined 10–135°, stramineous to orange-brown, long- and slender-pyriform, neck 1/2 urn length;

exothecial cells elongate-rectangular, walls straight;

stomata superficial;

annulus present;

operculum conic;

exostome teeth yellow-brown to red-brown, acute-triangular;

endostome hyaline, basal membrane 1/2 exostome length, segments broadly keeled, broadly perforate, cilia short to long.

inclined 80–100°, orange to orange-brown, slender-pyriform, neck 1/2 urn length;

exothecial cells elongate-rectangular, walls straight;

stomata superficial;

annulus present;

operculum conic;

exostome teeth yellow to orange-brown, acute-triangular;

endostome hyaline or rarely orange-brown, basal membrane 1/2 exostome length, segments tapered apically, broadly keeled, broadly perforate, cilia short to long.

Spores

18–26 µm, ± coarsely papillose.

16–22 µm, finely to distinctly roughened.

Specialized

asexual reproduction absent.

asexual reproduction typically absent.

Pohlia cruda

Pohlia nutans

Phenology Capsules mature summer (Jun–Aug). Capsules mature spring (Apr–Jun).
Habitat Soil banks, rock crevices, under roots, tundra soil and paths Soil banks, logs, tree bases, disturbed places
Elevation moderate to high elevations low to high elevations
Distribution
from FNA
AK; AZ; CA; CO; IA; ID; MA; MD; ME; MI; MN; MT; NC; NE; NJ; NM; NV; NY; OR; PA; SD; TN; UT; VA; VT; WA; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; QC; SK; YT; Mexico; South America; Australia; Greenland; Pacific Islands; Eurasia; Antarctica
[WildflowerSearch map]
from FNA
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; SK; YT; Africa; Greenland; Eurasia; Mexico (Nuevo León); Australia
[WildflowerSearch map]
Discussion

Pohlia cruda is distinguished by the glossy, pale green to whitish or bluish leaves that are narrowly elliptic to lanceolate; the laminal cells are long and narrowly linear-vermicular; the perichaetial leaves are strongly differentiated and linear-lanceolate; the sporophytes have necks about as long as the urn, with long-tapered exostome teeth, broadly keeled and perforate segments, and short to long cilia. Along with P. nutans, P. cruda is one of the most common North American species of the genus. Unlike P. nutans, P. cruda is restricted to northern and montane sites where it grows in rock crevices and on soil banks. The leaves of this species are sometimes slightly complanate. The gametophytes can be unisexual (dioicous) or bisexual (paroicous).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Pohlia nutans is the most common species of Pohlia in North America, Europe, and elsewhere in the Northern Hemisphere. In contrast to the treatment by A. J. Shaw (1982), P. sphagnicola is not separated here from P. nutans; the type of P. sphagnicola is European. Plants referable to P. sphagnicola, including North American collections, differ in being dioicous and having entire leaves, slightly shorter laminal cells, and smaller spores. The habitat in Sphagnum hummocks is not diagnostic; at least 80% of plants growing in Sphagnum are P. nutans. Pohlia schimperi, a northern form with reddish leaves, also dioicous, is not recognized, as per Shaw.

The peristome of Pohlia nutans is as well developed as any in Pohlia, with long, tapered, trabeculate exostome teeth and well-developed endostomes with broadly keeled, widely perforate segments and short to long cilia. The laminal cells are short- to elongate-hexagonal with thickened walls. The only other North American species with relatively thick-walled laminal cells is P. elongata; the cells of P. elongata are typically longer, but there is extensive overlap in sizes. Plants without sporophytes have generally been named P. nutans, although some collections from montane regions may actually be P. elongata; sporophytes of P. elongata have longer necks, as long as or longer than the urns, and reduced peristomes with endostome segments narrowly split along the keel and (usually) no cilia.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 28, p. 198. FNA vol. 28, p. 196.
Parent taxa Mielichhoferiaceae > Pohlia Mielichhoferiaceae > Pohlia
Sibling taxa
P. andalusica, P. andrewsii, P. annotina, P. atropurpurea, P. beringiensis, P. bolanderi, P. brevinervis, P. bulbifera, P. camptotrachela, P. cardotii, P. columbica, P. crudoides, P. drummondii, P. elongata, P. erecta, P. filum, P. flexuosa, P. lescuriana, P. longibracteata, P. longicolla, P. ludwigii, P. melanodon, P. nutans, P. obtusifolia, P. pacifica, P. proligera, P. rabunbaldensis, P. robertsonii, P. tundrae, P. vexans, P. wahlenbergii
P. andalusica, P. andrewsii, P. annotina, P. atropurpurea, P. beringiensis, P. bolanderi, P. brevinervis, P. bulbifera, P. camptotrachela, P. cardotii, P. columbica, P. cruda, P. crudoides, P. drummondii, P. elongata, P. erecta, P. filum, P. flexuosa, P. lescuriana, P. longibracteata, P. longicolla, P. ludwigii, P. melanodon, P. obtusifolia, P. pacifica, P. proligera, P. rabunbaldensis, P. robertsonii, P. tundrae, P. vexans, P. wahlenbergii
Synonyms Mnium crudum Webera nutans, P. sphagnicola
Name authority (Hedwig) Lindberg: Musc. Scand., 18. (1879) (Hedwig) Lindberg: Musc. Scand., 18. (1879)
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