151. Candelariella ] 38. LECANORACEAE 317 



exciple colored like the thallus, more or less irregular; hypothecium hyaline; 

 hymenium hyaline or brownish above ; paraphyses unbranched, more or less jointed 

 toward the apices; asci clavate; spores 8-many, hyaline, oblong to ellipsoid, non- 

 septate or rarely 1-septate. 



The algal host is Pleurococcus. 



A. Spores not more than 20 /* in length 

 B. Thallus granulose 



C. Thallus pale to lemon-yellow 4. C. crenulata 



C. Thallus not lemon-yellow 



D. Thallus greenish yellow to olive-green 3. C. cerinella 



D. Thallus greenish gray to blackish 2. C.aurella 



B. Thallus more or less squamulose, squamules forming 



areole-like clusters 1- C.vitellina 



A. Spores large, 25-46 fi in length 5. C. Spraguei 



1. Candelariella vitellina (Ehrh.) Mull. Arg., Bull. Herb. Boiss. 2: app. 47. 1894. 

 Lichen vitellinus Ehrh., PL Crypt. Exsicc. 155. 1785. Parmelia vitellina (Ehrh.) 



Ach. Placodium vitellinum (Ehrh.) Hepp. Pleochroma vitellina (Ehrh.) 



Clements. 



Thallus granulose or of small round to crenate-lobed squamules, scattered or 



continuous and forming areole-like clusters, bright greenish yellow; apothecia 



small to middle-sized, 0.3-1.3 mm. across, sessile, the disk flat, tawny-yellow to 



olive-green, the exciple of the same color as the .thallus, granulose-crenate ; spores 



commonly 12-32, rarely 8, non-septate or more commonly 1-septate, 8-16 X 4-7 /x. 



On rocks and old wood, throughout the United States. 



2. Candelariella aurella (Hoffm.) Zahlbr., Cat. Lich. Univ. 5:790. 1928. 



Verrucaria aurella Hoffm., Deutschl. Fl. 197. 1796. Lecanora epixantha (Ach.) 

 Nyl. Placodium vitellinum var. aurellum (Hoffm.) Tuck. 



Thallus thin and inconspicuous, greenish gray to blackish, smooth to rough, 

 soon scattered and often granulose, sometimes disappearing; apothecia minute to 

 small, 0.1-0.6 mm. across, adnate to sessile, the disk flat, tawny-yellow or orange 

 to olive-green, the exciple entire, lemon-yellow to orange or olive-green; spores 

 oblong-ellipsoid, frequently more than twenty in an ascus, often slightly curved, 

 non-septate or sometimes 1-septate, 8-14 X 4-6 //.. 



On rocks and old wood, from Ohio westward to California and Washington. 



3. Candelariella cerinella (Vainio) Zahlbr., in E. & P., Nat. Pfl. V-.IW. 1907. 

 Lecanora cerinella Vainio, Term. Fiiz. 22:284. 1899. 



Thallus thin, of more or less scattered round granules, greenish yellow to olive- 

 green; apothecia minute to small, 0.1-0.8 mm. across, sessile, the disk flat to convex, 

 greenish yellow, the exciple thin, greenish to bright yellow, entire to subcrenulate, 

 soon disappearing; spores oblong-ellipsoid, some slightly curved, non-septate to 

 obscurely 1-septate, 9-13 X 5-7 \x. 



On rocks and soil, Nevada, California, and Washington. 



4. Candelariella crenulata (Wahl.) Zahlbr., Cat. Lich. Univ. 5:812. 1928. 

 Lichen murorum var. crenulatus Wahl., Flora Lapp. 416. 1812. Placodium crenu- 



latum (Wahl.) Tuck. 



Thallus moderately thick, round, minutely granulose, crenately lobed, pale to 

 lemon-yellow; apothecia small to middle-sized, 0.4-0.8 mm. across, adnate to sessile, 

 often crowded, the disk flat to convex, pale to tawny yellow, the exciple thin, 

 colored like the thallus, becoming crenate ; spores 8 to many, ellipsoid, non-septate 

 to 1-septate, the cells polar, 9.5-15 X 4.5-7 [x. 



On rocks, Massachusetts and Colorado. 



5. Candelariella Spraguei (Tuck.) Zahlbr., Cat. Lich. Univ. 5:802. 1928. 

 Placodium Spraguei Tuck., Syn. N. A. Lich. 1:179. 1882. Lecanora Spraguei 



Tuck. 

 Thallus composed of short branches crowded into a papillate greenish yellow 

 crust, sometimes expanding into lobulate squamules toward the margin; apothecia 



