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bog haircap moss, hummock haircap, narrow-leaf haircap, polytrichum moss, slender haircap

juniper haircap moss, juniper polytrichum moss

Habit Plants slender, green to whitish green, dark brownish with age, in deep, compact tufts. Plants small to medium to fairly robust, gray-green to bluish green to reddish brown with age, in loose tufts, often forming extensive patches.
Stems

6–12(–20) cm, simple, densely matted with wooly whitish to light-brownish tomentum.

(1–)4–5(–10) cm, simple, brownish tomentose only near the base.

Leaves

2–5(–6) mm, erect to closely appressed when dry, erect-spreading when moist;

sheath oblong-rectangular, brownish, ± abruptly contracted to the blade;

blade narrowly lanceolate, acuminate, flat, with sharply infolded margins;

marginal lamina 6–7 cells wide, 1-stratose, entire to finely crenulate above, membranous and transparent, abruptly infolded and enclosing the lamellae and overlapping towards the apex;

costa toothed abaxially towards the apex, short-excurrent as a short, reddish brown awn;

lamellae bluntly crenate in profile, 5–8 cells high, the marginal cells in section pyriform, thick-walled, ending in a thickened knob, end cells of lateral lamellae ovoid and scarcely thickened at the apex;

sheath cells 45–80 × 7–10 µm, elongate-rectangular (5–7:1), narrower toward the margin;

cells of the marginal lamina transversely elongate, shorter and obliquely oriented towards the margins, very thick-walled and colorless.

3–6(–8) mm, densely imbricate, ± erect and almost straight when dry, erect-spreading to widely spreading when moist;

sheath oblong-rectangular, yellowish, tapering to the blade;

blade slender, bluish green and nitid, rather flat, with sharply infolded margins;

marginal lamina 5–7 cells wide, 1-stratose, entire or minutely crenulate, membranous and transparent, enclosing the lamellae and overlapping towards the apex;

costa usually somewhat toothed distally, excurrent, forming a subulate, toothed awn, the awn reddish brown throughout or slightly decolorate at tip;

lamellae bluntly crenate in profile, 6–8 cells high, the marginal cells in cross-section ovate to pyriform, thick-walled, ending in a distinct knob, smooth or rarely faintly papillose, the marginal cells of lateral lamellae (enclosed by the overlapping margins) ovoid and less strongly thickened;

sheath cells 70–100 × 6–10 µm, narrowly rectangular (4–6:1), narrower toward the margin;

cells of the broad marginal lamina transversely elongate, very thick-walled.

Seta

2–4 cm, yellowish to reddish brown.

(1–)3–5 cm, stout, yellowish to reddish brown.

Sexual condition

dioicous;

perichaetial leaves somewhat longer than the stem leaves, ending in a slender awn.

dioicous;

perigonial rosettes yellowish to reddish green;

perichaetial leaves longer than the foliage leaves, long-sheathing, the blade almost obsolete, ending in a slender yellowish or hyaline awn.

Capsule

2–3 mm, short-rectangular to almost cubic (1–1.5:1), brownish, sharply 4-angled and prismatic, suberect, becoming horizontal when ripe;

peristome 200–230 µm, divided to 0.8, the teeth 64, obtuse.

2.5–5 mm, rectangular, longer than wide (1.5–2:1), reddish brown to dark brown, glaucous when fresh, suberect, becoming horizontal when mature, sharply 4-angled and prismatic;

peristome 200–240 µm, divided to 0.6–0.8, the teeth 64, keeled at back.

Calyptra

dirty white to light brown, enclosing the capsule.

whitish to light brown, covering the capsule.

Spores

7–9(–15) µm.

6–10(–12) µm.

Polytrichum strictum

Polytrichum juniperinum

Habitat Sphagnum bogs, wet heaths and tundra, muskeg, sedge meadows, moist alpine tundra, also on local elevations and on rotten stumps in wet spruce forests Exposed, well-drained, mostly acid soils in old fields and open woods, in openings following forest fire, on trailside banks and road cuts, on thin shallow soil overlying rocks, blowdowns and open ridge tops near timberline, only rarely in moist or wet situations
Elevation low to high elevations low to high elevations
Distribution
from FNA
AK; CA; CO; CT; GA; IA; IL; IN; MA; MD; ME; MI; MN; MT; NC; NH; NJ; NY; OH; OR; PA; RI; UT; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; SK; YT; South America; e Asia (Russia, Japan); Atlantic Islands (Faroes, Iceland); Greenland; n Asia; n Europe (Scandinavia, Svalbard); Antarctica
[WildflowerSearch map]
from FNA
AK; AL; AR; AZ; CA; CO; CT; DE; GA; IA; ID; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MT; NC; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; YT; Mexico; Central America; c Asia; Australia; Pacific Islands (New Zealand); Atlantic Islands (Macaronesia); Greenland; n Asia; Europe; s South America; West Indies; Antarctica
[WildflowerSearch map]
Discussion

Polytrichum strictum is widespread in the boreal regions of the Holarctic, and is one of the commonest low arctic representatives of the family (D. G. Long 1985), with survivals southward in relict bogs, for example in northern Indiana, northern Illinois, and northwestern Iowa, also in alpine situations in the eastern mountains to the Carolinas and Georgia. In Nunavut, it is known from Baffin, Bathurst, and Devon islands. Its characteristic habitat is on hummocks in Sphagnum bogs, in deep masses tightly bound together by dirty-white, wooly tomentum, with short, stiffly erect leaves, and cubical capsules, a clear correlation between a distinctive morphology, distribution, and ecology.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Polytrichum juniperinum occurs on a variety of substrates, but primarily in dryer situations than P. commune or P. strictum. It often forms extensive pure stands of a distinctive pale bluish green color from the reflection of light off the thin, membranous margins of the leaves. The narrow leaf blades are widely spreading and have short, reddish awns. Polytrichum juniperinum is common and generally distributed throughout continental North America. In the high Arctic, however, the species is rare and many older reports of it actually pertain to 5. P. hyperboreum (D. G. Long 1985).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 27, p. 139. FNA vol. 27, p. 138.
Parent taxa Polytrichaceae > Polytrichum Polytrichaceae > Polytrichum
Sibling taxa
P. commune, P. hyperboreum, P. jensenii, P. juniperinum, P. piliferum, P. swartzii
P. commune, P. hyperboreum, P. jensenii, P. piliferum, P. strictum, P. swartzii
Synonyms P. affine, P. juniperinum var. affine, P. juniperinum var. gracilius P. alpestre, P. juniperinum var. alpestre, P. juniperinum var. waghornei
Name authority Bridel: J. Bot. (Schrader) 1800(1): 286. (1801) Hedwig: Sp. Musc. Frond., 89, plate 18, figs. 6–10. (1801)
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