Pohlia wahlenbergii |
Pohlia elongata |
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pale nodding-cap moss, pale pohlia, Wahlenberg's pohlia moss |
elongate pohlia moss, long-fruit pohlia, long-fruit thread-moss |
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Habit | Plants small to very large, whitish or sometimes in large forms reddish, dull. | Plants small, green, dull. |
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 ovate-lanceolate, 2 mm; margins subentire or more often serrulate to serrate in distal 1/3; costa subpercurrent or percurrent; distal medial laminal cells hexagonal to rhomboidal, firm, 45–85 µm, walls moderately thick. |
Seta | orange-brown. |
orange to orange-brown. |
Sexual condition | dioicous; perigonial leaves ovate; perichaetial leaves weakly differentiated, lanceolate. |
paroicous, autoicous, or rarely dioicous; perigonial leaves in dioicous plants broadly short-ovate; perichaetial leaves somewhat differentiated, ± long-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 10–90°, stramineous, orange, or orange-brown, short- to long- and slender-pyriform, neck 1/2–1 time urn length; exothecial cells elongate-rectangular, walls straight; stomata superficial; annulus present; operculum conic; exostome teeth yellow to brown, acute-triangular; endostome hyaline, basal membrane barely exceeding capsule rim or to 1/3 exostome length, segments narrowly or not keeled, narrowly to not perforate, cilia absent to rudimentary, rarely long. |
Spores | 15–21 µm, finely roughened. |
16–23 µm, distinctly roughened. |
Specialized | asexual reproduction absent. |
asexual reproduction absent. |
Pohlia wahlenbergii |
Pohlia elongata |
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Phenology | Capsules mature spring (Apr–Jun). | Capsules mature spring–summer (Apr–Jul). |
Habitat | Disturbed clay or rarely sandy soil, path banks, along streams | Humus-rich soil banks, along streams and paths, tree bases |
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; AL; AZ; CA; CO; GA; IA; ME; MI; MN; MT; NC; NH; NM; NY; OH; TN; UT; VA; VT; WA; WI; BC; NB; NL; NS; NT; ON; QC; YT; Mexico; Central America; South America; Eurasia; Africa; Pacific Islands; Australia |
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 elongata is widespread in North America but not common. Plants generally occur scattered or in small patches and regularly produce sporophytes from bisexual (paroicous) gametophytes. The capsule necks of P. elongata are typically longer than the urn and the endostome is reduced (see under 1. P. nutans). The endostomial segments vary from relatively broad and distinctly keeled with narrow perforations to narrowly linear, scarcely keeled, and not at all split along the keels. A high elevation expression that has generally been collected from exposed sites and often called P. acuminata or P. polymorpha, is characterized by small plants with relatively broad leaves and short, barrel-shaped sporophytes with short necks. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 28, p. 212. | FNA vol. 28, p. 197. |
Parent taxa | Mielichhoferiaceae > Pohlia | Mielichhoferiaceae > Pohlia |
Sibling taxa | ||
Synonyms | Hypnum wahlenbergii, Mniobryum wahlenbergii | P. acuminata, P. elongata var. greenii, P. polymorpha |
Name authority | (F. Weber & D. Mohr) A. L. Andrews: in A. J. Grout, Moss Fl. N. Amer. 2. 203. (1935) | Hedwig: Sp. Musc. Frond., 171. (1801) |
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