Acarospora obnubila
Acarospora obnubila ("cloudy cobblestone lichen") is a dull brown squamulose areolate crustose lichen that may grow up to 4 mm in diameter or with squamules scattered among other lichens.[1]:217[2] They are common in Arizona, southern California, and Baja California.[2] They grow by themselves on acidic rock in full sunlight.[2] Squamules measure up to 2 mm in diameter and are round to irregular, with have a stipe.[2][1]:217 They may also grow on members of the genus Aspicilia (lichenicolous).[2] Competition for space with other lichens stimulates longer stipes to develop,[2] whereby the squamules may overlay other lichens.
| Acarospora obnubila | |
|---|---|
 | |
| Closeup of fertile areoles at 30X magnification | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Acarosporales |
| Family: | Acarosporaceae |
| Genus: | Acarospora |
| Species: | A. obnubila |
| Binomial name | |
| Acarospora obnubila H.Magn. (1929) | |
There are 0-16 apothecia per squamule, that may are pointlike (punctiform) with a reddish-brown round concave 0.1–0.3 mm disc that is deeply immersed in the thallus tissue.[2] In very high elevations, the apothecia may rise as warty (verrucae) structure with thallus-like tissue (pseudo-lecanorine ) collaring discs that may be up to 1 mm diameter, with only one per squamule.[2] Lichen spot tests are all negative, with no known secondary metabolites (as of 2014).[2] A. obnubila was first described scientifically by lichenologist Adolf Hugo Magnusson in 1929.[3]
References
- Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, ISBN 978-0-300-19500-2
- Lichen Flora of the Greater Sonoran Desert Region. Vol 3., Nash, T.H., Ryan, B.D., Gries, C., Bugartz, F., (eds.) 2001,
- Magnusson AH. (1929). "A monograph of the genus Acarospora". Kongliga Svenska Vetenskapsakademiens Handlinger. 7 (4 (III)): 263.