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Ptilium crista-castrensis
The non-costate, falcate-secund, strongly plicate leaves are key features. Sanionia uncinata has similar leaves, but has a costa and denticulate leaves. Microscopically, no other peatland species has the strongly plicate leaves and lacks a costa. Hypnum xxx, a species of tundra habitats would be somewhat similar, differing in alar cell features.
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L to R : Ptilium crista-castrensis in the field, alar cells, apex, and whole leaf |
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| Habit | Large, erect, regularly pinnately branched plants forming yellow-green triangular fronds. |
| Stems | densely covered in leaves, without paraphyllia or tomentum of rhizoids. |
| Leaves | falcate-secund, plicate, costa very short and double, margins serrulate above. |
| Leaf Cells | elongate to linear, smooth. |
| Alar Cells | not much differentiated, shorter and thick-walled with a few cells at the angles pale and thin-walled forming inconspicuous groups. |
| Habitat | Infrequent in the upland boreal forest, becoming rare coastward, rare or lacking in the north. In peatlands, sometimes present on hummocks in peat plateaus and heavily shaded bogs. |
| Common Associates | This species occurs in peatlands with Pleurozium schreberi and Hylocomium splendens. |
pH Meter
