Evernia
Evernia Ach., 1809
| Common name | Oakmoss Lichens |
|
|---|---|---|
| Field Characters | Fruticose, shrubby chlorolichens. Usnic yellow to pale green, often mottled. Branches angular and ridged to flattened, often soft and pliable. Cortex typically soft and dull, more rarely stiff and brittle. Medulla cottony, like a filling in a stuffed animal. Soredia common in many species, apothecia very rare. | |
| Similar genera |
Ramalina: cortex shiny, stiff and striate, ‘combed’ in appearance.
Usnea: has an elastic central cord. Alectoria: stiff and hair-like, with raised linear pseudocyphellae Pseudevernia: silvery grey |
|
| Ecology | Epiphytic, mainly on conifers and shrubs in forested regions. Rarely found on the ground or rock in alpine/tundra and grassland environments. | |
| Chemistry | Cortex PD-, K-, KC+ oily yellow (usnic acid), medulla all spot tests negative (evernic or divaricatic acid) | |
| Molecular support |
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| Links |
Species recorded in Alberta: 4
- E. divaricata (L.) Ach. (rare, higher elevation and/or wetter sites)
- E. mesomorpha Nyl. (province-wide, common)
- E. prunastri (L.) Ach. (rare, close to BC border)
- E. perfragilis Llano (arctic)
DICHOTOMOUS KEY – Based on Goward 1999, Brodo et al. 2001
1a. Branches clearly flattened and dorsiventral, with whitish lower surface; round soralia on lobe margins and upper surface with coarse soredia; rare in AB, confirmed to date from few sites close to the BC border…..E. prunastri
1b. Branches not flattened, angular or irregular in section; sorediate or not…..2
2a. Thallus bushy, typically erect, branches bearing isidia or soredia, or both on ridges; common across AB forested regions and even found occasionally on soil or rock in alpine and grassland sites…..Evernia mesomorpha
2b. Thallus either pendant or prostrate; branches lacking isidia and soredia; rare in AB and more common in mountains and foothills regions…..3
3a. Thallus prostrate over soil in alpine; branches hard-corticate, brittle; medulla dense…..Evernia perfragilis
3b. Thallus pendant, epiphytic, more rarely prostrate on soil in the mountains; branches soft-corticate, supple; medulla lax (epiphytic) or dense (terricolous)…..Evernia divaricata
RENR Students: Know Evernia mesomorpha – be able to key this species out or recognize it (it is also covered in Brodo et al. 2001 and Goward 1999).
Gallary
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- Evernia mesomorpha, Opal Natural Area, AB
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- Evernia mesomorpha on Poplar, near Smith, AB
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- Evernia divariacata, Hinton, AB
