102 — 
ARTIFICIAL KEY TO SPECIES.* 
*The method of using this form of Key may be illustrated by taking as an example a 
specimen of our typical lichen, with the characters of which we are already familiar. 
Out of the four alternatives given under “1,” we find that only that marked “c,” 
describes our specimen. This refers us to Section 12. Here we find that “c” is the 
alternative that fits, and this refers us to “15.” Under 15 we must choose “a” and 
thence we go to 16, and from “16a” to “17a” which gives us the name, Parmelia con- 
spersa. 
1. a. Th. cladoniseform, podetia hollow 2 
b. Th. fruticulose or when young cladoniseform, and the podetia becom- 
ing fruticulose by the disappearance of the horizontal th. at least 
from the base 5 
c. Th. foliaceous or foliaceous-squamulose 12 
d. Th. crustaceous . 21 
2. a. Ap. brown , 3 
Ap. scarlet or orange .'. 4 
3 a. Podetia 3-6 cm. tall, dilated above into shallow cups, bearing apothe- 
cia on the rim, and from the centre giving rise to similar stalked 
cups ; very smooth throughout. On the earth. 
Cladonia gracilis var. verticillata. 
b. Podetia 5-25 mm. tall, top-shaped, short stalked, the margin spreading, 
bearing sessile or stalked ap. ; granulose, warty or scurfy. On the 
earth, etc. Cladonia pyxidata. 
c. Podetia 1-3 cm. tall, goblet-shaped, rather long-stalked and slender, 
the margin erect, often with tooth like projections sometimes bear- 
ing ap.: cortex disintegrating into a fine glaucous- white powder. 
On the earth, etc Cladonia fimbriata. 
4. a. Podetia cylindrical, sometimes branched, mostly about 2-4 mm. tall; 
smooth or with the surface wrinkled. On dead wood, etc. 
Cladonia cristatella. 
b. Podetia elongated-top-shaped, about 15-35 mm. tall; smooth, becom- 
ing warty. On the earth.... Cladonia Cornucopioides. 
5. a. Branches cylindrical and hollow. ........ 6 
b. Branches not hollow 7 
6. a. Podetia about 3-6 cm. tall, branches about .5-1 mm. thick, several 
times forked, awl-shaped at the top, with a smooth firm cortex, 
brown above, becoming gray in the lower (older) portions. On the 
earth .... Cladonia furcata var. subulata. 
b. Podetia about 4-10 cm. tall, branches about .5-1.5 mm. thick, the di- 
visions mostly wide-spreading, the sterile tips curved and drooping; 
ecorticate, the surface fibrohs, sometimes appearing mealy or warty; 
ashy white or tinged with greenish straw color. On the earth, often 
forming extensive mats. (Called “ Reindeer Moss” from its form- 
ing the winter food of that animal.) Cladonia rangiferina. 
7. a. Th. softish, cottony within 8 
b. Th. cartilaginous 9 
8. a. Branches angular-terete or flattened, often sorediiferous, greenish or 
straw-colored, sometimes paler below. Mostly on dead wood and 
(with us) sterile Everina brunastri • 
