Pohlia nutans |
Pohlia columbica |
|
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nodding pohlia, nodding thread-moss, pohlia moss |
pohlia moss |
|
Habit | Plants small to large, green or rarely reddish, dull. | Plants small to medium-sized, green to reddish, dull. |
Stems | 0.5–3.5(–10) cm. |
0.4–1.5 cm, green to pale orange or pink. |
Leaves | 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. |
erect-spreading to spreading, narrowly lanceolate to lanceolate, 1.2–2.5 mm; base not or scarcely decurrent; margins serrate in distal 1/3; costa subpercurrent; distal medial laminal cells linear-hexagonal, 85–150 µm, walls thin. |
Seta | orange to orange-brown. |
orange-brown. |
Sexual condition | paroicous, rarely dioicous; perigonial leaves ovate-lanceolate; perichaetial leaves somewhat differentiated, ± long-lanceolate. |
dioicous; perigonial leaves to 3 mm; perichaetial leaves ± differentiated, lanceolate to linear-lanceolate. |
Capsule | 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. |
inclined 145–180°, brown to 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 yellow to yellow-brown, triangular-acute; endostome hyaline, basal membrane 1/2 exostome length or slightly longer, segments tapered apically, distinctly keeled, broadly perforate, cilia long and nodulose, or short. |
Spores | 16–22 µm, finely to distinctly roughened. |
13–18 µm, finely roughened. |
Specialized | asexual reproduction typically absent. |
asexual reproduction absent. |
Pohlia nutans |
Pohlia columbica |
|
Phenology | Capsules mature spring (Apr–Jun). | Capsules mature spring (May–Jul). |
Habitat | Soil banks, logs, tree bases, disturbed places | Disturbed soil, along streams |
Elevation | low to high elevations | low elevations |
Distribution |
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
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AK; WA; BC |
Discussion | 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.) |
Pohlia columbica is a very rare and poorly known species characterized by dull reddish plants, variably long-acuminate perigonial leaves, pale yellow-brown exostome teeth, and immersed stomata. The exothecial cell walls of capsules of this species are somewhat collenchymatous; the perichaetial leaves are 3 mm long. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 28, p. 196. | FNA vol. 28, p. 209. |
Parent taxa | Mielichhoferiaceae > Pohlia | Mielichhoferiaceae > Pohlia |
Sibling taxa | ||
Synonyms | Webera nutans, P. sphagnicola | Webera columbica |
Name authority | (Hedwig) Lindberg: Musc. Scand., 18. (1879) | (Kindberg) A. L. Andrews: in A. J. Grout, Moss Fl. N. Amer. 2: 202. (1935) |
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