Polytrichum

1 Leafy shoots not above 2.5 cm. tall, usually 1.5 cm. or less — 2

Leafy shoots 2-7 cm. tall; leaf margin entire or toothed; habitat heaths and well-drained exposed places — 5

Leafy shoots 5-25 cm. tall; leaf margin toothed; habitat wet moorland or woods —7

2 Longest leaves less than 3 mm., incurved towards tips; on fine gravelly acid detritus on mountains. Leaf structure a bit like Polytrichum (when moist), when dry margins incurved — Oligotrichum hercynicum

Leaves longer, not incurved towards tips — 3

3 Plant pale bluish green (glaucous) above, stems up to 6 cm; capsule cylindrical.  — Pogonatum urnigerum (= Polytrichum urnigerum)

Leaves with broad light-coloured margin (5-15 cells wide), otherwise like slightly smaller P. formosum. Can also look a bit like Atrichum undulatum. Infertile peat. – Polytrichum longisetum.

Plant lacking glaucous hue and broad margin — 4

4 Leafy shoot not more than 1 cm. tall; dark green leaves without hair-points, in spreading rosette like miniature aloe plant; capsule cylindrical — Pogonatum aloides (= Polytrichum aloides)

Leafy shoot rather taller; leaves with hair-points; capsule 4-angled — P. piliferum

5 Plant glaucous above; leaf margin serrate; no hair-point, capsule cylindrical — Pogonatum urnigerum (= Polytrichum urnigerum)

Plant dark green; leaf margin entire (check several plants); leaves may have hair- points; capsule 4-angled, sandy ground (burnt heath) — 6

6 Leaves with whitish hair-points, loose sand (inland dunes, 'stuifzand') — Polytrichum piliferum

Whitish hair-points lacking; leaves ending in short but acute reddish-brown points — Polytrichum juniperinum

(P. juniperum is separated by some authorities into 2 species or sub-species; P. alpestre=P juniperum subsp. strictum has taller stems (8-12 cm), shorter leaves and white tomentum covering the stems. It is found on boggy moorland)

7 Chiefly on wet moorland, open places; leaf sheath 'metallic', glossy; plants often over 15 cm. tall; lamellae top cell with dent — Polytrichum commune

Chiefly in dry to moist woods; leaf sheath dull; plants rarely more than 9 cm. tall; rounded lamellae top cell — Polytrichum formosum

Polytrichum piliferum

 

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