Pohlia wahlenbergii |
Pohlia bulbifera |
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pale nodding-cap moss, pale pohlia, Wahlenberg's pohlia moss |
blunt-bud pohlia, blunt-bud thread-moss, pohlia moss |
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Habit | Plants small to very large, whitish or sometimes in large forms reddish, dull. | Plants small to medium-sized, green, glossy. |
Stems | 0.8–10 cm. |
0.3–3 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, lanceolate, 0.9–1.4 mm; margins serrulate to serrate in distal 1/3; costa subpercurrent; distal medial laminal cells rhombic to rhomboidal, 65–95 µm, walls thin. |
Seta | orange-brown. |
orange-brown. |
Sexual condition | dioicous; perigonial leaves ovate; perichaetial leaves weakly differentiated, lanceolate. |
dioicous; perigonial leaves ovate; perichaetial leaves scarcely differentiated, 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 95–180°, brown to stramineous, pyriform, neck 1/3 urn length; exothecial cells short-rectangular, walls sinuate; stomata superficial; annulus present; operculum convex-conic; exostome teeth yellow-brown, narrowly triangular-acute; endostome hyaline, basal membrane 1/2 exostome length, segments distinctly keeled, broadly perforate, cilia short to rudimentary. |
Spores | 15–21 µm, finely roughened. |
16–21 µm, finely roughened. |
Specialized | asexual reproduction absent. |
asexual reproduction usually present when sterile; axillary gemmae 2–6, spheroid to obovate, shorter than leaves, yellow, orange, or green, leaf primordia restricted to apex and forming dome, laminate. |
Pohlia wahlenbergii |
Pohlia bulbifera |
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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 | Acid, gravelly or sandy disturbed soil, path banks, stream banks, peaty soil |
Elevation | low to high elevations | low 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; CO; MA; ME; MI; NH; NY; VT; WA; WI; BC; MB; NB; NL; NS; NT; ON; QC; Greenland; Eurasia |
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.) |
The gemmae of Pohlia bulbifera appear to be round to oblong because the four or five laminate leaf primordia are concave and form a dome over the gemma apex. The leaves are wide-spreading so the gemmae, although small, can be seen clustered in the distal leaf axils. This species sometimes occurs on peaty soils in bogs but also occurs on gravelly soils in disturbed places. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 28, p. 212. | FNA vol. 28, p. 206. |
Parent taxa | Mielichhoferiaceae > Pohlia | Mielichhoferiaceae > Pohlia |
Sibling taxa | ||
Synonyms | Hypnum wahlenbergii, Mniobryum wahlenbergii | Webera bulbifera |
Name authority | (F. Weber & D. Mohr) A. L. Andrews: in A. J. Grout, Moss Fl. N. Amer. 2. 203. (1935) | (Warnstorf) Warnstorf: in C. F. Warnstorf et al., Krypt.-Fl. Brandenburg 1: 429. (1904) |
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