Status: Native
Synonyms:
None
Polytrichum commune is a bogdweller, unlike the other two members of the genus in New Mexico.
Polytrichum juniperinum and Polytrichum piliferum both grow on rock or drier soil and litter.
P. commune leaves have hyaline sheathing leaf bases, and the leaf margins are not expanded and therefore
do not cover the laminae that arise from the costa. The margins of the leaf have sharp teeth.
The apical cell of each of the laminae is broader than the cells below and retuse-- that is, it is indented downwards from
the top. In profile, the upper edge of a lamina looks wavy (crenate). From above, each laminal sheet appears
to be topped by two messy, minute rows of knobs. Polytrichum commune is found at the edges of bogs where it
may be mixed with Sphagnum.
Please click on an image for a larger file.
Polytrichum commune, habit, photo Russ Kleinman & Karen Blisard, Valles Caldera, July 3, 2019
Polytrichum commune, mixed with Sphagnum fimbriatum, photo Russ Kleinman & Karen Blisard, Valles Caldera, July 3, 2019
Polytrichum commune, photomicrograph of leaf, photo Russ Kleinman & Karen Blisard, Valles Caldera, July 3, 2019
Polytrichum commune, photomicrograph of leaf cross section showing flattened costa with more than 20 guide cells, leaf margin not enclosing laminae, and marginal tooth, photo Russ Kleinman & Karen Blisard, Valles Caldera, July 3, 2019
Polytrichum commune, photomicrograph of leaf showing retuse apical cell of laminae, photo Russ Kleinman & Karen Blisard, Valles Caldera, July 3, 2019
Polytrichum commune, photomicrograph of leaf marginal teeth, photo Russ Kleinman & Karen Blisard, Valles Caldera, July 3, 2019
Polytrichum commune, photomicrograph of lamina showing crenate upper surface in profile (to the left), photo Russ Kleinman & Karen Blisard, Valles Caldera, July 3, 2019
Polytrichum commune, photomicrograph of leaf from above showing each lamina topped by two messy rows of knobs, photo Russ Kleinman & Karen Blisard, Valles Caldera, July 3, 2019
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