THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 149 



KEY TO SPECIES. 



A. Thallus usually of minute, steel-blue granules 4. cyanolepra 



A A. Thallus more or less brown, of evident squamules. 

 B. Thallus of minute to very minute squamules passing into a con- 

 tinuous areolate crust i. microphylla 



BB. Squamules small to medium size, crenate lobulate. 



C. Squamules as in BB 2. lepidiota 



CC. Squamules passing into a mass of short, stout, coralloid branch- 

 lets 3. lepidiota coralliphora 



i. PARMELIELLA MICROPHYLLA (Sw.) MM. Arg. 



Lichen microphyllus Swartz, Vet. Ak. Handl. 301. 1791. 



Parmeliella microphylla Mull. Arg., 



Pannaria microphylla Tuck. Syn. N. Am. Lich. I: 121. 1882. 



Thallus of minute to very minute, closely appressed, crenate, 

 often imbricate squamules which are mostly run together into a 

 continuous or areolate-chinky crust; sometimes thinly scattered; 

 on a blue-black hypothallus; upper surface of squamules a yellow- 

 brown, with whitish margins, so that the whole crust has an ashy 

 brown appearance. 



Apothecia very numerous, small to medium size, from plane soon 

 convex, appressed, the disk pale to dark red-brown, sometimes 

 blackening; the paler, entire, proper margin soon excluded; when the 

 thallus is well developed and thick the apothecia are sub-immersed 

 with a pseudo-thalline margin of denticulate squamules; when the 

 thallus is thin they are superficial; epithecium pale yellow; para- 

 physes loosely coherent ; thecium bluish, then a nondescript yellowish- 

 reddish or tawny yellowish with I; spores long ellipsoid, /< 



20 30 



Common on sandstone and also occurring on roots in the foot- 

 hills and mountains. Differing from the type in the very much 

 larger spores and the reduced squamules, the forma calijornica of 

 Tuckerman. 



I am not satisfied with placing it here, but can find no other place 

 for it. 



P. microphylla is a common lichen of the mountains of the tem- 

 perate and sub-arctic realms. 



