316 



38. LECANORACEAE [149. Phlyctella 



pruinose, the exciple thin, colored like the thallus, becoming powdery; hypothecium 

 hyaline to pale brownish; spores 1, hyaline to brownish, oblong with round ends, 

 19-35-septate transversely and S-9-septate longitudinally, 100-170X32-46^. 

 On trees, New Hampshire, Oklahoma, Washington, Oregon, and California. 



3. Phlyctis Willeyi Tuck., in Nyl., Lich. Jap. 106. 1890. 



Thallus thin, smooth to slightly uneven, becoming chinky, ashy gray to whit- 

 ish; apothecia minute, 0.15-0.25 mm. across, immersed, the disk concave to flat, 

 black, the exciple rather thick, colored like the thallus, becoming wavy; hypothe- 

 cium hyaline to yellowish; spores 1, hyaline, oblong, 9-25-septate transversely and 

 4-6-septate longitudinally, 92-130 X 32-60 /x. 



On trees, Florida and Texas. 



149. Phlyctella Kremph., Verh. Zool. Bot. Gesell. 26:452. 1876. 



Thallus crustose, smooth to rough, chinky, areolate or powdery, the upper 

 cortex usually wanting, the algal layer indistinct, the medullary layer of loosely 

 interwoven, thin-walled hyphae, attached to the substratum by hyphal rhizoids; 

 apothecia minute to small or middle-sized, immersed to adnate, the disk concave 

 to flat, the exciple colored like the thallus, thin to thick, irregular; hypothecium 

 hyaline to yellowish or brownish; hymenium hyaline or brownish above; paraph- 

 yses unbranched and free; asci clavate; spores 1-8, hyaline, several-many-septate, 

 the cells lenticular. 



The algal host is Pleurococcus. 



1 Phlyctella andensis Nyl, Lich. Nov. Zeal. 73. 1888. 



Phlyctis andensis Nyl., Bull. Soc. Linn. Norm. II. 2:514. 1868. Platygrapha 

 phlyctella Nyl. 



Thallus thin, white, obscurely chinky; apothecia small, 0.3-0.6 mm. across, be- 

 coming sessile, round to angular or irregular, the disk flat, grayish pruinose to 

 black, the exciple thin, brownish black, surrounded by a thin, whitish, thalloid 

 one; hypothecium hyaline; spores 8, hyaline, fusiform, 5-7-septate, 35-45 X 5-7 jx. 



On trees, Florida. 



150. Phlyctidia Mull. Arg., Hedwigia 34:141. 1895. 



Thallus crustose, smooth to rough, chinky, areolate or powdery, the upper 

 cortex usually wanting, the algal layer indistinct, the medullary layer of loosely 

 interwoven, thin-walled hyphae, attached to the substratum by hyphal rhizoids; 

 apothecia minute to small or middle-sized, immersed to adnate, the disk concave 

 to flat, the exciple colored like the thallus, thin to thick, irregular; hypothecium 

 hyaline to yellowish or brownish; hymenium hyaline or brownish above; paraph- 

 yses irregularly and netlike interwoven; asci clavate; spores 1-8, hyaline, oblong 

 to ellipsoid, several-many-septate, the cells lenticular. 



The algal host is Pleurococcus. 



1. Phlyctidia ludoviciensis Mull. Arg., Hedwigia 34:141. 1895. 



Thallus thin, smooth to minutely warty, becoming wrinkled and areolate, ashy 

 white; apothecia minute, 0.1-0.25 mm. across, round to somewhat irregular, some- 

 times 'clustered, immersed to adnate, the disk flat, flesh-colored to brown or grayish 

 pruinose, the exciple colored like the thallus, thick, irregular; spores 1, hyaline, 

 oblong-ellipsoid, 11-19-septate, the cells appearing irregularly pitted, 85-100 X 

 25-30 ix. 



On trees, Louisiana. 



151. Candelariella Mull. Arg., Bull. Herb. Boiss. 2:11. 1894. 



Thallus crustose, smooth to rough, granulose, warty, areolate, sometimes lobed 

 at the margins, scarcely differentiated or showing poorly developed upper cortex and 

 medullary layer, attached to substratum by hyphal rhizoids; apothecia small to 

 middle-sized, adnate to sessile, the disk concave to flat or slightly convex, the 



