124 17. DIRINACEAE [64. Dirina 



64. Dirina E. Fries, Syst. Orb. Veg. 244. 1825. 



Thallus crustose, the cortex composed of erect, non-septate hyphae, the medulla 

 attached to the substratum by hyphal rhizoids; apothecia round, irregular, or 

 elongated, with thin proper exciple and thick thalloid one; hypothecium thick, 

 black or dark brown, stroma-like; paraphyses unbranched or sparingly branched 

 toward the apex; asci usually clavate; spores 8, hyaline, finger-shaped to spindle- 

 shaped, several-septate. 



The algal host is Trentepohlia. 



A. Spores constantly 3-septate 



B. Spores less than 20 fi in length 



C. Thallus greenish gray to whitish 2. D. California 



C. Thallus cream-colored to whitish, sometimes lobed 



at the margin 4. D. Hassei 



B. Spores more than 20 /x in length 3. D. franciscana 



A. Spores 3-9-septate 1. D. rediunta 



1. Dirina rediunta (Stizenb.) Zahlbr., Ann. Naturh. Hofmus. Wien. 16:82. 1901. 

 Lecanora rediunta Stizenb.. Erythea 4:107. 1896. Lecidea sublugcns Nyl. 

 Thallus thin and smooth to thicker and chinky-areolate, greenish gray to ashy, 



finally crumbling more or less; apothecia small to middle-sized, 0.3-0.8 mm. across, 

 sessile, the disk flat to convex, more or less whitish pruinose to black, the thalloid 

 exciple colored like the thallus, rarely crenate and disappearing, exposing a proper 

 exciple; hypothecium thick and dark brown; spores fusiform, bluntly pointed, 

 3-9-septate, 20-25 X 4-6 /*. 



On trees, along the coast and on Santa Catalina Island. California. 



2. Dirina California Tuck., Lich. Calif. 17. 1866. 

 Schizmatomma California (Tuck.) Herre. 



Thallus moderately thick, greenish gray to whitish, becoming rough and chinky 

 to subareolate; apothecia small to middle-sized, 0.5-1 mm. across, sessile, usually 

 crowded, the disk flat to slightly convex, grayish pruinose and dirty black, the 

 exciple wavy to crenulate and becoming more or less flexuous; hypothecium 

 blackish brown, 2 or 3 times as thick as the hymenium, stroma-like; asci long- 

 clavate; spores 3-septate, finger-shaped, 14-18 X 3-4.5 /j.. 



On trees, southern California. 



3. Dirina franciscana Zahlbr.; Herre, Bot. Gaz. 43:270. 1907. 



Thallus thick, irregularly tuberculate-warty, forming heaped patches, greenish 

 gray to ashy or brownish yellow; apothecia middle-sized to large, 0.4-2.5 mm. 

 across, sessile, becoming numerous and nearly covering the thallus, the disk flat 

 to slightly convex, granulate or furrowed, grayish pruinose to dirty black, the 

 exciple thick, prominent, colored like the thallus or more commonly whitish, 

 becoming intricately flexuously irregular, and nearly disappearing; hypothecium 

 dark brown, as thick as the hymenium, those of adjacent apothecia often coa- 

 lescing in stroma-like fashion; spores finger-shaped, often curved, 3-septate, 

 25-34 X 5-8.5 fi. 



On soil, southern California. 



4. Dirina Hassei Zahlbr., Bull. Torr. Club 27:644,645. 1900. 



Thallus thin, often somewhat wrinkled, becoming chinky-areolate, dull cream- 

 colored to whitish, the margin sometimes obscurely lobed; apothecia small, 0.3-0.7 

 mm. across, sessile, the disk flat to somewhat convex, more or less grayish pruinose 

 or finally black, the exciple thin and whitish; hypothecium dark brown, reaching 

 2 or 3 times the thickness of the hymenium and stroma-like; asci cylindrico-clavate, 

 becoming saccate or wedge-shaped; spores often slightly curved, fusiform with 

 obtuse ends, 3-septate, 15-20 X 3-4 /a. 



On trees, along the seashore near Santa Monica, California. Very close to 

 D. California Tuck. 



OTHER SPECIES REPORTED 

 Dirina Catalinariae Hasse — California. 



