108 HERRE 



limiting hypothallus, which is often indistinct; color varying from 

 brownish to bluish or blackish gray; KOH ; CaCl 2 2 . 



Apothecia minute to small, often crowded, innate or very closely 

 adnate; often concentrically arranged; the flat black disk surrounded 

 by a thickish, elevated, entire or irregular, slightly paler margin; per- 

 manent in our specimens though said to be finally excluded; hypo- 

 thecium brown or blackish brown; thecium dark blue with I, the color 



12 13 



evanescent; spores oblong, 4-locular to muriform, dusky, - - /< 



according to Tuck., 8 1 8 by 24 40^. 



On rocks in the foothills and mountains, in dry localities. Gen- 

 erally distributed over Europe and North America. 



CLADONIACE^E. 



Thallus from crustaceous and uniform to foliaceous, usually incon- 

 spicuous, of horizontal or ascendant, more or less leafy squamules, or 

 these reduced and only granulose. Apothecia borne on the tips of 

 upright hollow or solid podetia, which form the "plant;" they may 

 be simple, club, cup, or funnel-shaped, or shrub-like and much 

 branched. Spores colorless, simple to 100 celled, or muriform. 

 But one genus in our limits. 



XXIV. Cladonia (Hill.) Wainio. 



Cladonia Hiller, Hist. PI. 91. 1751, in part. 

 Cladonia Wainio, Monog. Clad. Univ. 1:5. 1887. 

 Cladonia Tuck. Syn. N. Am. Lich. I: 236. 1882. 



Podetia hollow, exceedingly variable, cup, club, or funnel shaped, 

 or shrub-like and much branched; apothecia cephaloid, scattered or 

 confluent, red, brown, or flesh-colored, borne on the tips of the pode- 

 tia; spores simple, ovoid-oblong, small, much alike in all the species. 



An exceedingly difficult genus from the highly variable and poly- 

 morphic species which seem to intergrade in a manner most puzzling. 

 The group is considered to be one of recent origin and it is probable 

 that many of the forms are still undergoing rapid changes and that the 

 species have not become relatively fixed. This is highly interesting 

 to the ecologist and physiologist but is grievous to the systematist. 

 My material has been passed upon by several workers of recog nized 



