Umbilicaria polaris (Schol.) Zahlbr., 1932
| Common name | Polar Rock Tripe |
|---|---|
| Code | UMBIPOL |
| Field Characters | Foliose, umbilicate chlorolichen. Rounded, to sligtly lobate thalli typically less than 4 cm across. Upper surface with radially spreading network or “frosty” ridges and valleys. The “frost” is actually very coarse crystals of pruina. Lower cortex smooth, gray, tan to brown, smooth, lacking rhizines. Isidia and soredia lacking. Apothecia common, sessile, scattered across the upper surface; with a central hole or sterile button-like area which may be obscure when mature. This is a key trait, so check multiple apothecia on a thallus. |
| Similar species & genera |
Two other Umbilicaria in Alberta have apothecia with a sterile central button. U. virginis can be discriminated by its abundant rhizines. U. decussata has a sooty black lower cortex, versus the typically grey to tan lower surface of U. polaris. If you do not see a sterile central button in the apothecia, this species could be mistaken for U. rigida or U. lyngei, but these species have apothecia that are stipitate (on short stalks). |
| Ecology | Saxicolous on noncalcareous rock in the mountain region of Alberta. Occurrences to date are largely from Jasper, Banff and Waterton National Parks. Typically in alpine to subalpine habitats. |
| Chemistry | |
| Molecular support |
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| Links | |
| Gallery | See links above |
