THE BRYOLOGIST. 
Vol. X. July, 1907 No. 4 . 
FURTHER NOTES ON CLADON1AS. XI. 
Cladonia pyxidata and Cladonia pityrea. 
Bruce Fink. 
Cladonia pyxidata is perhaps as easy to distinguish as any of our Cla- 
donias, but it is sometimes confused with forms of Cladonia fimbriata , espe- 
cially C. fimbriata shnplex, which has rather short podetia and large cups 
for ihe species. Some of our best workers in American lichenology have also 
confused Cladonia pyxidata with immature and sterile specimens of Cla- 
donia deformis. This species could likewise be confused easily with the 
northern alpine Cladonia carneola. 
Cladonia pityrea is little known in America, and the writer can only 
state his own difficulties with the species. Of the forms submitted to Dr. 
Wainio, he had supposed the one from Iowa to be an unusual condition of 
Cladonia cristatella, two of those from Minnesota had been doubtfully 
referred to Cladonia fimbriata , and the others were recognized as very 
unusual Cladonias"and sent without attempt at determination. 
After a careful study of the effects of KOH on the thalli of Cladonias, 
the writer is convinced that in many instances these chemical tests are of 
considerable supplementary value in spite of differences due to age of thalli, 
differences in substrata, etc. However, in all of the species mentioned 
above, the KOH test is always or most usually negative or nearly so, so that 
its use in diagnosis, would be of very little or no value. In a supplementary 
paper, at the close_of this series, the writer will give the results of his studies 
with KOH so that they may be used to supplement the diagnoses. 
The specimen of Cladonia pyxidata that furnishes the illustration for 
this paper was collected by the writer at Tower, Minnesota, and determined 
by Dr. Wainio. That for Cladonia pityrea was collected near Hofheim, Ger- 
many, by L. Scriba, and determined by him as follows: “ Cladonia pityrea 
(Flk.) Fr. inter 5. cladomorpham Floerk. et 6. hololepidem (Flk.) Wainio.” 
Cladonia pyxidata (L.) Hoffm. Deutschl. FI. 121. 1796. Primary th al- 
ius commonly persistent, composed of irregularly or digitately incised or 
lobate, flat, concave or rarely convex, commonly ascending, clustered or scat- 
tered squamules, which are 2-8 mm. long and 1.5-6 mm. wide, sea-green 
above or varying toward whitish or olivaceous, commonly lighter and sore- 
diate below. Podetia arising from the surface of the primary thallus, 3.5-30 
mm. long and 3-4.5 mm. in diameter; turbinate or tubaeform, erect; the 
cortex areolate, or verrucose, or subcontinuous toward the base; frequently 
more or less decorticate toward the top, rarely more or less squam- 
ulose; sea-green varying toward ashy or olivaceous: the decorticate portion 
white or ashy-brown: frequently closely clustered; cup-bearing. Cups 1-7 
mm. in diameter, regular or irregular; on well developed podetia or the dila- 
The May BRYOLOGIST was issued May 2 , 1907. 
