Pohlia nutans |
Pohlia brevinervis |
|
---|---|---|
nodding pohlia, nodding thread-moss, pohlia moss |
pohlia moss |
|
Habit | Plants small to large, green or rarely reddish, dull. | Plants very small to small, whitish, somewhat glossy. |
Stems | 0.5–3.5(–10) cm. |
0.3–1.5 cm. |
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, lanceolate, 0.6–1.4 mm; base not or scarcely decurrent; margins serrulate in distal 1/3; costa subpercurrent; distal medial laminal cells linear-rhomboidal, 60–110 × 6–9 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 weakly differentiated, 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 ± 180°, brown to stramineous, short-pyriform to urceolate, neck less than 1/3 urn length; exothecial cells isodiametric, walls sinuate; stomata superficial or slightly immersed; annulus absent; operculum short- to long-conic; exostome teeth dark to light brown or red-brown, triangular-acute; endostome light yellow, basal membrane 1/2 exostome length or slightly longer, segments tapered apically, distinctly keeled, broadly perforate, cilia long, nodulose. |
Spores | 16–22 µm, finely to distinctly roughened. |
16–21 µm, finely roughened. |
Specialized | asexual reproduction typically absent. |
asexual reproduction absent. |
Pohlia nutans |
Pohlia brevinervis |
|
Phenology | Capsules mature spring (Apr–Jun). | Capsules mature spring (Apr–Jun). |
Habitat | Soil banks, logs, tree bases, disturbed places | Clay soil along streams, ditches, glacial outwash |
Elevation | low to high elevations | low to high 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
|
AK; AB; YT; Asia (e Siberia) |
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 brevinervis is a rare and poorly known species that seems to combine characters of P. vexans (erect, glossy leaves on sterile plants) and P. atropurpurea (dark, reddish brown exostome teeth and somewhat immersed stomata). The leaves are distinctly more whitish than those of P. vexans. The exothecial cell walls of capsules of this species are somewhat collenchymatous. (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 | |
Name authority | (Hedwig) Lindberg: Musc. Scand., 18. (1879) | Lindberg & Arnell: Kongl. Svenska Vetensk. Akad. Handl., n. s. 23(10): 51. (1890) |
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