Identification notes
P. piliferum is a small but usually gregarious species of all sorts of sunny, well-drained acidic places, where it often grows with similarly desiccation-tolerant bryophytes such as Ceratodon purpureus.
Like its similar relative, P. juniperinum, its shoots are typically no more than 2-3 centimetres tall and it has entire leaf margins. Even cursory examination with a hand-lens will reveal at least some leaves (usually the younger ones) with the hyaline excurrent nerve that gives it its name. It is this feature that distinguishes it from all related species.
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