Pohlia wahlenbergii |
Pohlia cruda |
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pale nodding-cap moss, pale pohlia, Wahlenberg's pohlia moss |
opal pohlia, opal thread-moss, pohlia moss |
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Habit | Plants small to very large, whitish or sometimes in large forms reddish, dull. | Plants medium-sized to large, green, whitish, or sometimes bluish tinged, shiny. |
Stems | 0.8–10 cm. |
0.5–2.5 cm. |
Leaves | laxly spreading to more stiffly erect, lanceolate to ovate-lanceolate, 0.6–1.2 mm; margins weakly to strongly serrulate in distal 1/3; costa ending well before apex; distal medial laminal cells laxly and broadly hexagonal to rhomboidal, 65–110 µm, walls thin. |
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. |
Seta | orange-brown. |
orange to orange-brown. |
Sexual condition | dioicous; perigonial leaves ovate; perichaetial leaves weakly differentiated, lanceolate. |
paroicous, rarely dioicous; perigonial leaves in dioicous plants linear- or long-lanceolate from ovate base; perichaetial leaves strongly or rarely weakly differentiated, linear-lanceolate. |
Capsule | inclined ± 180°, brown to red-brown, sometimes stramineous, short-pyriform to urceolate, neck less than 1/3 urn length; exothecial cells isodiametric, walls sinuate; stomata immersed; annulus absent; operculum short- to long-conic; exostome teeth light brown to red-brown, triangular-acute; endostome hyaline to yellow, basal membrane 1/2 exostome length or slightly longer, segments tapered apically, distinctly keeled, broadly perforate, cilia long, nodulose. |
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. |
Spores | 15–21 µm, finely roughened. |
18–26 µm, ± coarsely papillose. |
Specialized | asexual reproduction absent. |
asexual reproduction absent. |
Pohlia wahlenbergii |
Pohlia cruda |
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Phenology | Capsules mature spring (Apr–Jun). | Capsules mature summer (Jun–Aug). |
Habitat | Disturbed clay or rarely sandy soil, path banks, along streams | Soil banks, rock crevices, under roots, tundra soil and paths |
Elevation | low to high elevations | moderate to high elevations |
Distribution |
AK; AR; AZ; CA; CO; CT; DC; IA; ID; IL; KS; KY; LA; MA; MD; ME; MI; MN; MO; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; SD; TN; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; YT; Mexico; Central America; South America; Greenland; Eurasia; Antarctica
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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
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Discussion | Pohlia wahlenbergii is one of the most geographically widespread and common species of the genus. The leaves are pale whitish, decurrent, and have lax, thin-walled cells. The species varies greatly in size from very slender delicate plants in suboptimal habitats to large and deep cushions in cold high altitude and latitude sites. Large plants of P. wahlenbergii typically have red stems and sometimes reddish pigmentation to the leaves as well. Some authors refer large expressions to var. glaciale (or P. glaciale), but gradation in size and pigmentation is completely continuous, and different collectors draw the line between the typical variety and var. glaciale at different points. The exothecial cell walls in capsules of this species are somewhat collenchymatous. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 28, p. 212. | FNA vol. 28, p. 198. |
Parent taxa | Mielichhoferiaceae > Pohlia | Mielichhoferiaceae > Pohlia |
Sibling taxa | ||
Synonyms | Hypnum wahlenbergii, Mniobryum wahlenbergii | Mnium crudum |
Name authority | (F. Weber & D. Mohr) A. L. Andrews: in A. J. Grout, Moss Fl. N. Amer. 2. 203. (1935) | (Hedwig) Lindberg: Musc. Scand., 18. (1879) |
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