29¢ BOTANICAL GAZETTE [OCTOBER 
confused, the uncertainty arising on account of the doubt as to what ACHARIUS 
meant by his Lichen cereolus, described in Lichenographia Suecicae Prodromus 
(1798), p. 89, and figured as Stereocaulon cereolus in Methodus Lichenum (1803), 
pl.7, fig. 1. In Tu. Frtes’s Monograph (1858), p. 40, the treatment is confused, 
S. cereolus being placed as a variety under S. cereolinum (Ach.) Koerb., of 
which S. pileatum is made a synonym, apparently disregarding priority. 
But in his Lichenographia Scandinavica (1871), p. 55, TH. FRtes states that 
‘according to the original specimens in Acwartus’ Herbarium, Lichen cereolus 
is synonymous with Pilophorus Fibula Th. Fr. This would leave S. pileatum 
the oldest name and the one to be adopted, as has indeed been done by TH. 
Fries (0p. cit.) and most recent authors. 
Stereocaulon pileatum is closely allied to S. condensatum, with which, as 
indicated in the synonymy, it was at one time united by certain authors, yet 
the differences between the two are greater than those between S. paschale 
and S. tomentosum, which have been recognized as distinct since the work of 
Exias Fries. The points of difference are as follows. 
S. pileatum S. condensatum 
. Squamules typically coralline. 1. Squamules granular. 
2. Podetia simple and reduced. . Podetia stouter, often branched 
laa] 
is) 
. above. 
3. Apothecia often replaced by sore- 3. Apothecia never replaced by sore- 
dia. dia. 
. Spores with blunt ends, and aver- 4. Spores with pointed ends, and 
aging 4 in width. averaging 2.7 # in width. 
Growing on rocks. . Growing on soil. 
S. pileatum also shows a strong resemblance to forms of Pilophorus. 
When fertile the spore differences will of course serve for their distinction. 
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tk 
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2. STEREOCAULON CONDENSATUM Hoffm. 
S. condensatum Hoftm. Deutsch. Fl. 2:130. 1795. 
Primary thallus persistent, formed of coarse, rounded granules, 
intermixed with conspicuous black masses of Stigonema, with which 
are formed dark, rugose cephalodia; podetia stout, simple or 
fastigiately branched above; squamules granular, rarely coralline; 
apothecia well developed; spores 20-28X 2.5-3 B, average 23% 
2,.6 ¢, with pointed ends.—Growing on soil. 
SPECIMENS EXAMINED : 
Europe: Fries Lich. Suec. no. 88; Schaer. Lich. Helv. no. 599) _ 
Lich. Ital. Suppl. no. 29; Nyl. and Norrl. Herb. Lich. Fenn. no. 87- 
Canapa: Labrador, A. P. Low July 21, 1896 (Can); Quebec, robes 
Aug. 11, 1905 (Can). 
