318 39. PARMELIACEAE [ 152. Candelaria 



middle-sized, 0.8-1.5 mm. across, subsessile, the disk flat to slightly convex, dull 

 brownish yellow, the exciple thick, colored like the thallus, becoming flexuous and 

 crenate; spores 8, 1-septate, ellipsoid to acicular, irregularly broken within, 

 25-46 X 3-5 /x. 



On soil over rocks, Colorado, Montana, and Washington. 



OTHER SPECIES REPORTED 

 Candelariella rosulans (Mull. Arg.) Zahlbr. — Colorado. 



39. PARMELIACEAE 



Thallus foliose, or rarely fruticose, differentiated into cortical, algal, and 

 medullary layers, attached to the substratum by rhizoids, or the under surface 

 rarely bearing cyphellae or densely covered with a mass of darkened hyphae; 

 apothecia round, sessile, or somewhat pedicellate, with well-developed thalloid 

 exciple. 



The algal hosts are Pleurococcus and Protococcus. 



A. Upper cortex plectenchymatous 



B. Thallus yellow; spores many in each ascus 152. Candelaria 



B. Thallus rarely yellow; spores commonly 8 in each ascus 



C. Thallus more or less upright; apothecia marginal .... 155. Cetraria 



C. Thallus flat; apothecia not marginal 154. Parmelia 



A. Upper cortex of interwoven hyphae 153. Parmeliopsis 



152. Candelaria Mass., Flora 35:567. 1852. 



Thallus foliose, more or less irregularly lobed, commonly yellow, differentiated 

 into upper and lower plectenchymatous cortices, a thin algal layer, and a medullary 

 layer of thin-walled, intertangled hyphae, attached to the substratum by short 

 rhizoids; apothecia small to middle-sized, sessile, the disk concave to flat, commonly 

 yellow or brownish, the exciple prominent, colored like the thallus, becoming 

 somewhat irregular; hypothecium hyaline or brownish; hymenium hyaline to 

 brownish above; paraphyses spongy, unbranched or rarely forked toward the 

 somewhat enlarged apices; asci broadly clavate; spores many (16-32), hyaline, 

 ellipsoid to ovoid-ellipsoid, non-septate or rarely becoming 1-septate. 



The algal host is Pleurococcus. 



A. Exciple not fibrillose below 



B. Thallus much lobed 1. C. concolor 



B. Thallus reduced to granulose squamules or passing 



into a powdery crust 1. C. concolor effusa 



A. Exciple fibrillose below 2. C. fibrosa 



1 Candelaria concolor (Dicks.) Am., Flora 62:364. 1879. 



Lichen concolor Dicks. PL, Crypt. Brit. 3:18. pi. 9, f. 8. 1793. Parmelia pari- 

 etina var. concolor (Dicks.) E. Fries. Physcia candelaris Nyl. Teloschistes 

 concolor (Dicks.) Tuck. C. laciniosa var. effusa (Tuck.) Riddle. 



Thallus round to irregular, greenish yellow to yellow or ashy, composed of 

 many, small, scattered or more or less imbricated lobes, these often passing into 

 a continuous crust toward the center, and becoming narrow and much divided 

 toward the circumference, with finely granulose, slightly ascending margins; ashy 

 below, bearing minute, ashy rhizoids and marginal fibrils; apothecia small, 0.5- 

 1.5 mm. across, subsessile, the disk concave to flat, yellow or becoming brownish, 

 the exciple thin to rather thick, colored like the thallus, becoming crenulate; 

 hypothecium hyaline; spores numerous, hyaline, oblong, becoming 1-septate, 

 6-1 1 X 3-5 fi. 



On trees, throughout the United States. 



