THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 51 



DIDYMELLA FALLAX Wainio. 



Arthopyrenia fallax Nyl. Flora, 363. 1872. 



This fungus, long considered to be a lichen, but which is apparently 

 not a lichen as it seems to lack algae, is common on the trunks and 

 limbs of smooth-barked trees in the foothills. It may be recognized 

 as follows: Thallus thin, rather effuse, forming smooth, whitish, 

 cream-colored or pale olive patches; sprinkled with the minute, black, 

 sub-globose, sessile or half-innate apothecia; paraphyses hair-like, 

 free, simple and straight or branched and more or less twining; I ; 

 asci elongate, brownish with I; spores bilocular or becoming 4-locular, 



cons ricted at the middle, l p . 



I2j 20 



4. ARTHOPYRENIA CINEREO-PRUINOSA (Schaer.) Jatta. 



Verrucaria cinereo-pruinosa Schaerer, Spicilegia, 342. 1836. 

 Arthopyrenia cinereo-pruinosa Jatta, Syll. Lich. Ital. 529. 1900. 



Thallus diffuse, thin, uniform, pale gray t ) olivaceous; KOH yellow; 

 CaCl 2 2 -. 



Apothecia rcatter.d, black, small to minute, more or less immersed 

 and s ssil , hemispherical or sub-globose; covered with the epidermal 

 thalline layer, and hence ashy-pruinose, or naked; perithecium dimi- 

 diate, black, thickish; paraphyses branched and twining, or simple; 



I - ; spares bilocular, pointed and slender ellipsoid, /*. 



12 - 15 



On the bark of Umbellularia californica, in Stevens Creek Canon. 

 The above seems to be a variety of this European lichen, characterized 

 by mailer spores than the type. 



Section ACROCORDIA. 



Apothecia solitary, hemispherical, globular, or conical; paraphyses 

 permanent, hair-like, twining and net-like; asci cylindrical or ventri- 

 cose, the spores of 2 similar cells arranged in a single row. 



