FINK—THE LICHENS OF MINNESOTA. 227 
pale or brownish above; paraphyses rarely branched toward the apex, this seldom 
thickened or colored; asci clavate or cylindrico-clavate; spores oblong to ellipsoid, 
frequently curved, 28 to 43 » long and 16 to 22 4 wide. 
A rare plant in Minnesota, collected in the northern portion of the State at Two 
Harbors, Tower, and Harding. 
Little is known of the North American distribution. Reported from California and 
from Florida, otherwise apparently confined to the northern United States and north- 
ward, and much less common than the subspecies below. Possibly all of our Minne- 
sota material could be referred to the subspecies, but undoubted specimens of the type 
have been found as near Minnesota as northeastern Iowa. Known also in Europe and 
Asia. 
4a. Physcia aquila detonsa (Fr.) Tuck. Syn. N. A. Lich. 1:71. 1882. 
Parmelia detonsa Fr. Syst. Orb. Veg. 284, 1825. 
Thallus pale or darker brown, rarely isidioid or much more frequently the lobes 
fringed with small lobules; the borders of the apothecia also frequently fringed with 
similar lobules. Internally like the above. 
Number 1024 from Koochiching shows exciples externally ciliate, a character not 
seen in descriptions. 
This is the usual form in Minnesota and, though by no means common, is generally 
distributed over the State. On trees and rarely on rocks. 
Distributed throughout the eastern half of the United States and northward. Also 
known in Japan. 
5. Physcia pulverulenta (Schreb.) Nyl. Act. Soc. Linn. Bord. 21: 308. 1856. 
Lichen pulverulentus Schreb. Spic. Fl. Lips. 128. 1771. 
Thallus medium-sized but sometimes large, 2.5 to 6 cm, in diameter, but rarely 
reaching 10 cm., usually closely adnate but with margins occasionally somewhat 
ascendant, stellate; the upper surface smooth, the lobes sometimes quite elongated 
and narrow, with ends rounded or crenate; sea-green to brown or completely or inter- 
ruptedly white-pruinose, beneath variously colored but usually brownish black and 
lighter toward the margin, the numerous rhizoids black or brown, or lighter toward the 
margins; apothecia small or middle-sized, 2.5 to 5 mm. in diameter, sessile, the disk flat 
or concave, and dark brown or subpruinose, the margin entire, crenate or irregularly 
lobed; hypothecium pale or yellowish; hymenium pale below and pale or brownish 
above; paraphyses simple or rarely branched toward the apex, which is sometimes 
thickened and brownish; asci clavate; spores oblong to ellipsoid, 22 to 40 long and 
12 to 20” wide. 
Generally distributed over the State. On trees, old wood, or rocks, or rarely over 
mosses on earth. 
Found in some form throughout North America. Known to all of the grand divi- 
sions except Australia and South America. 
5a. Physcia pulverulenta leucoleiptes Tuck. Syn. Lich. N. E. 32. 1848. 
Lobes more flattened, interruptedly elevated and pruinose at the margins, beneath 
black. 
Found only in the extreme northern portion of the State. On trees and rocks. 
Recorded from several widely separate North American localities and doubtless as 
widely distributed as the species. I find no record of the plant in foreign lands. 
6. Physcia stellaris (L.) Nyl. Syn. Meth. Lich. 1: 424. 1858. Puate 47, B. 
Lichen stellaris 1. Sp. Pl. 1144. 1753. 
Thallus, medium-sized, 20 to 85 mm. in diameter, closely adnate, stellate, the 
upper surface commonly smooth, the lobes frequently elongated and much branched, 
the ends rounded or crenate, more or less imbricate and frequently crowded into a 
