Arctoparmelia centrifuga (L.) Hale, 1986
| Common name | Concentric Ring Lichen |
|---|---|
| Code | ARCTCEN |
| Field Characters | Leafy, yellow chlorolichen. Thalli appressed, forming concentric rings due to senescence of older regions. Lobes narrow, angular, irregularly branching, typically to 0.5 cm across. Upper cortex dull, pale yellow in younger lobes, darkening in older lobes. No vegetative propagules. Lower cortex white to pale brown with sparse simple rhizines. Apothecia common, relatively large, on short stipes, with brown disc and thin yellow thalline margins (lecanorine). |
| Similar species & genera |
Arctoparmelia separata: lower cortex grey to black or purplish black (check towards the centre of the thallus, not at the lobe tips).
Arctoparmelia incurva, A. subcentrifuga: sorediate. Parmeliopsis ambigua: sorediate. Xanthoparmelia: rhizines commonly branched, lower cortex often black or dark brown (vs. white), cortices often shiny, medulla often PD+ orange to red. |
| Ecology | Saxicolous, typically on granitic rock, very very rarely on downed wood. Largely restricted to the shield and mountain regions of Alberta, with sparse occurrences in the boreal and foothills. |
| Chemistry | Upper cortex KC+ yellow, K+ yellow, C-, PD- or PD+ pale yellow, UV- (usnic acid, atranorin). Medulla KC+red, K-, C-, PD-, UV+ white (alectoronic acid). AB collections TLCed: 5. |
| Molecular support |
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