Nephroma arcticum (L.) Torss., 1843
| Common name | Green Paw |
|---|---|
| Code | NEPHARC |
| Field Characters | Yellowish green cephalolichen. Thalli flattened to ruffled with downturned lobes and cephalodia. Cephalodia can be quite cryptic, often visible as greyish bumps beneath the cortex. Upper cortex usnic yellow or a darkened gray where cephalodia are present; flattened to irregularly wrinkled, and lacking vegetative propagules. Lower cortex a pale tan near the edges and darkening to brown-black at the center. Lower surface texture smooth or short-tomentose, but always lacking rhizines. Apothecia common, on the lower surface of often reflexed lobe tips, large, with a brown, kidney-shaped disc, vaguely resembling the paw pads of a dog. |
| Similar species |
Other Nephroma species: Nephroma arcticum and Nephroma expallidum are unique in their genus as green algae dominant cephalolichens. N. expallidum has a more brownish green upper surface that is KC-, the cephalodia are less visible, and apothecia are rare. Other Nephroma species in Alberta are cyanolichens and lack cephalodia and tend toward a brownish-gray colour rather than a greenish-yellow.
Peltigera species carry their apothecia on the upper surface of their lobes. |
| Ecology | Terricolous in conifer forests, most common in the mountains. |
| Chemistry | Upper cortex KC+ yellow, K- or K+ pale yellow, C-, PD-, UV- (usnic acid), medulla KC-, K- or K+ pale yellow, C- or C+ pale yellow, PD+ deep yellow, UV- (zeorin, nephroarctin, phenarctin). |
| Molecular support |
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| Links | |
| Gallery |
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- Nephroma arcticum
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- Nephroma arcticum, Ambler Mountain near Grande Cache, AB
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- Nephroma arcticum, tundra, Samuel Glacier Hike, Tatsenshini-Alsek Provincial Park, BC
