111. Parmeliella ] 30. PANNARIACEAE 173 



toward the center; grayish to brownish below; apothecia minute, 0.15-0.25 mm. 

 across, the disk concave to flat, brown, the exciple colored like the thallus, soon 

 disappearing; spores 1-septate, oblong-ellipsoid, somewhat curved, 13-20X3-5/*. 

 On calcareous rocks, Alabama. 



OTHER SPECIES REPORTED 



Placynthium dubium Herre — California. 



111. Parmeliella Mull. Arg., Mem. Soc. Phys. et Hist. Nat. 

 Geneve 16:376. 1862. 



Thallus squamulose to crustose, smooth to rough, more or less irregularly lobed, 

 resting upon a well-developed, bluish black hypothallus or attached to the sub- 

 stratum by short rhizoids, differentiated into a plectenchymatous upper cortex of 

 vertical-extending hyphae, and irregular algal and medullary layers; apothecia 

 small to middle-sized, partly immersed to adnate or sessile, the disk flat to convex, 

 the exciple colored like the disk, often disappearing; hypothecium hyaline to 

 brownish; hymenium hyaline or brownish above; paraphyses unbranched; asci 

 clavate; spores 8, hyaline, oblong or ellipsoid, non-septate. 



The algal host is Nostoc. 



A. On rocks and soil 



B. Thallus composed of squamules, often passing into a granulose crust 

 C. Squamules and lobes dichotomously much-branched 



D. Thallus lead-gray 1. P. crossophylla 



D. Thallus greenish gray to straw-colored 3. P. cheiroloba 



C. Squamules and lobes more or less irregular 

 D. Thallus more or less gray-sorediate 



E. Squamules marginally warty 2. P. lepidiota 



E. Squamules passing into irregularly swollen 



branchlets 2. P. lepidiota corallophora 



D. Thallus not sorediate 



E. Squamules greenish gray to ashy or ashy brown 

 F. Squamules rather thin ; apothecia not more than 



1 mm. across 5. P. microphylla 



F. Squamules thicker; apothecia reaching 



1.5 mm. across 5. P. microphylla californica 



E. Squamules dark yellowish brown 9. P. ruderatula 



B. Thallus composed of granules 6. P. cyanolepra 



A. On trees 



B. Spores 14-24 /j. in length 



C. Squamules irregularly lobed toward the circumference . . . 7. P. plumbea 



C. Squamules passing into a densely granulose crust . . . 4. P. corallinoides 



B. Spores 5-10 fi in length 8. P. stellata 



1. Parmeliella crossophylla (Tuck.) Merrill & Burnh., Bryologist 25:36. 1922. 



Pannaria crossophylla Tuck., in Nyl., Ann. Sci. Nat. Bot. IV. 12:295. 1859. 



Thallus composed of small, dichotomously much-branched, imbricated, margin- 

 ally ascending, lead-gray squamules, passing centrally into a subsquamulose or 

 granulose, warty crust; blackening toward the center below; apothecia small to 

 middle-sized, 0.5-1 mm. across, immersed to partly superficial, the disk flat to 

 convex, flesh-colored to chestnut-brown, the exciple thin, colored like the disk, 

 soon disappearing; hypothecium hyaline; spores ellipsoid, 17-23 X 6-10 /a. 



On rocks, from Vermont to Alabama, and westward to Illinois. 



2. Parmeliella lepidiota (Sommerf.) Vainio, Term. Fiiz. 22:308. 1899. 



Lecidea carnosa var. lepidiota Sommerf., Suppl. Fl. Lapp. 174. 1826. Pannaria 

 lepidiota (Sommerf.) T. Fries. 



Thallus composed of small to middle-sized, closely imbricated, crenately lobed, 

 marginally warty and gray-sorediate, gray to brownish or blackening squamules, 

 those of the central portion often ascending and passing into a granulose, gray, 

 powdery crust; brownish to brown below, a bordering black hypothallus evident 



