THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 1 29 



Apothecia small or minute, sessile and biatorine, or enclosed in the 

 thallus and apparently pyrenocarpous ; paraphyses well developed 

 or absent; spores colorless or brown, simple or bilocular. 



KEY TO GENERA. 



A. Thallus fruticose, without cortex. 

 B. Thallus fiMform fruticose, decumbent, the apothecia lateral, sessile. 



XXVIII. Zahlbrucknera 

 BB. Thallus erect, Uke a minute shrub, always sterile with us. 



XXIX. Ephebe 

 A A. Thallus foHaceous or fruticose with well developed cortex. 



XXX. Polychidium 



XXVIII. Zahlbrucknera Herre, new genus. 



Thallus minutely fruticulose, decumbent, mat-like, the branches 

 thread-like, of Stigonema algae, the hyphae running parallel length- 

 wise in the gelatinous sheath. 



Apothecia small, lecideine, lateral, appressed, sub-globose; hypo- 

 thecium clear; paraphyses slender, sparingly branched or simple, 

 septate, their tips not enlarged; asci cylindrical to subclavate, elon- 

 gate, their tips often pointed, thin-walled, with from 8 to 24 spores; 

 these simple, globose to ellipsoid, thin walled, without a halo, at last 

 dusky or blackish. Spermatia not observed. 



Differs from Thermutis, to which it is nearest, in the paraphyses, 

 the multisporous asci, and the darkening spores. 



Named for Dr. Alexander Zahlbruckner, the eminent lichenolo- 

 gist, curator of the botanical section of the Imperial Natural His- 

 tory Museum, at Vienna, Austria. 



I. ZAHLBRUCKNERA CALCAREA Herre, new species. 



Thallus minute, almost microscopic, of thread-like, entangled, 

 branching, decumbent filaments, forming dense clumps or mats; 

 color black or blackish brown; becoming brown when moistened; 

 KOH -;CaCl202 -. 



Apothecia rare, minute, sub-globose, concolorous, the disk depres- 

 sed, very narrow, or with entire margin; paraphyses not numerous, 



■ 9-75 — 17 

 1.5 — 2 ,« broad; asci ix ; no reaction with I; spores 



80 — 108 

 8 to 24, usually i8, globose, ovoid, and ellipsoid, mostly colorless but 



