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Psora pseudorussellii Timdal
Family: Psoraceae
Psora pseudorussellii image
Stephen Sharnoff  
Squamules: up to 4 mm wide, elongate, imbricate, weakly concave to weakly convex upper surface: medium brown, dull or shiny, epruinose or partly pruinose, smooth or sparingly fissured margin: white, straight or up-turned, entire or lobed upper cortex: up to 90-140 µm thick, composed of thick- to thin-walled hyphae with angular to round lumina, containing crystals of calcium oxalate medulla: containing calcium oxalate lower cortex: of mainly periclinally oriented hyphae, not containing calcium oxalate lower surface: white to pale brown Apothecia: up to 1.5 mm diam., laminal-submarginal, plane and marginate when young, later becoming more convex and often immarginate, reddish brown, epruinose or yellow pruinose ascospores: ellipsoid, 8-12 x 5-7 µm Pycnidia: unknown Spot tests: upper cortex and medulla K-, C-, KC-, P- Secondary metabolites: none detected. Substrate and ecology: on calciferous rock in open habitats, at 790-1720 m World distribution: mediterranean Europe and North America Sonoran distribution: uncommon in Arizona, Chihuahua, Sinaloa and Sonora. Notes: Some specimens are difficult to distinguish from P. tuckermanii. The apothecia of Psora pseudorussellii are more reddish brown, less convex and often partly marginate (especially when young); the squamules are generally smaller and usually somewhat darker than those of P. tuckermanii. The two species are largely allopatric: P. pseudorussellii has a mainly eastern and southern and P. tuckermanii a mainly western distribution in North America (Timdal 1986).
Psora pseudorussellii image
Samuel Brinker  
Psora pseudorussellii image
Troy McMullin  
Psora pseudorussellii image
Troy McMullin  
Psora pseudorussellii image
Andrew Khitsun  
Psora pseudorussellii image
Stephen Sharnoff  
Psora pseudorussellii image
Stephen Sharnoff  
Psora pseudorussellii image
Stephen Sharnoff  
Psora pseudorussellii image
Stephen Sharnoff  
Psora pseudorussellii image
Stephen Sharnoff  
Psora pseudorussellii image
Stephen Sharnoff  
Psora pseudorussellii image
Psora pseudorussellii image
Psora pseudorussellii image
Psora pseudorussellii image
Psora pseudorussellii image
Psora pseudorussellii image
Psora pseudorussellii image
Psora pseudorussellii image