Physcia affinity stellaris (L.) Nyl., 1856, sp. nov.
| Common name | Star Rosette Lichen | |
|---|---|---|
| Codes |
PHYSSTE (for now) | |
| Field Characters | Small, foliose, chlorolichens. Thalli grey to white, composed of appressed, irregular rosettes with narrow lobes typically ≤0.6 mm wide. Lobes grasping and convex, with the lobe centre ever-so-slightly elevated above the margins. Upper cortex matte, sometimes spotted with abundant, white maculae, or occasionally pruinose. Vegetative propagules absent. Cilia absent. Lower cortex present, white to pale brown. Rhizines typically concentrated towards lobe margins, simple or sparsely branched, white to brown. Apothecia common, with brown to black pruinose to epruinose discs, thalline margin relatively thick and concolorous with the upper cortex, short-stipitate in the centre of the thallus. | |
| Similar species |
Physcia aipolia, Physcia alnophila: lobes plane to slightly concave, apothecia more adnate with thinner thalline margins, often more maculate (but not always) and with a more blue-grey upper cortex, medulla K+ yellow. | |
| Ecology | Abundant epiphyte on a variety of hosts and on downed wood, occasionally saxicolous. Widely distributed, most common in the boreal, parkland and grassland. Rare in the mountains, foothills and shield regions, | |
| Chemistry | Upper cortex K+ yellow, KC-, C-, PD- or PD+ pale yellow, UV- (atranorin), medulla all spot tests negative (carefully remove cortex from the area to test so that your medullary test is not contaminated with cortical metabolites). | |
| Molecular support |
Unpublished molecular results by T. Esslinger and S. Leavitt show that what we call P. stellaris in Alberta is actually at least one undescribed species, maybe more. Stay tuned! | |
| Links | ||
| Gallery |
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- Physcia stellaris, Edmonton region, AB
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- Physcia stellaris, close-up of convex lobe, Edmonton, AB
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- Physcia stellaris, K spot test results: K- medulla, K+ yellow cortex
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- Physcia stellaris, Edmonton, AB
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- Physcia stellaris, Edmonton, AB
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- Physcia stellaris, close-up of stipitate apothecia, Edmonton, AB
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- Physcia stellaris, ALTA collection
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- Physcia stellaris, close-up of apothecia, ALTA collection
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- Physcia stellaris, large colony on Populus balsamifera, Elk Island National Park, AB
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- Physcia stellaris, Edmonton, AB
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- Physcia stellaris, Edmonton region, AB
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- Physcia stellaris, Edmonton region, AB
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- Physcia stellaris, Lac la Biche region, AB
