162 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
5. Peltigera scutata (Dicks.) Leight. Lich. Fl. Great Brit. 110. 1871. 
Lichen scutatus Dicks. Pl. Crypt. Brit. 3: 18. 1793. 
Thallus much as in the last, but not so uniformly smooth and sometimes having 
trichomatic hyphz over at least portions of the upper surface, rather small to middle- 
sized, 6 to 14.5 cm. in diameter, the margins of the lobes usually rounded, crisped 
and frequently isidioid-granulate or isidioid-lobulate (not sorediate in ours), the fer- 
tile ones short and scattered, sea-green varying toward ashy or brownish, beneath 
light with brown veins, or in ours the whole lower surface, except the margins, becom- 
ing dark brown; apothecia rather smaller than in the last, orbicular or transversely 
oblong, the disk reddish brown; spores 4 to 8-celled, 50 to 70 » long and 3 to 4 « wide. 
Typical forms not fruited in ours, and spore and apothecial characters taken from 
Tuckerman. 
Recorded from Minneapolis and Taylors Falls as Peltigera pulverulenta (Tayl.) 
Nyl.¢ The best forms seem to differ sufficiently from either of the last two, but in 
the absence of fruit, the plants here recorded must be regarded as uncertain. A 
peculiar feature both in Iowa and Minnesota plants is the fact that the thallus is 
quite commonly found growing over blackened, dead thalli of the same kind, some- 
times three or more layers thus appearing one above another. On earth, usually 
under trees. 
Seems to be widely distributed in North America, though not often collected. 
Known also in Europe. 
6. Peltigera malacea Ach. Syn. Lich. 240. 1814. 
Thallus rather more loosely attached to the substratum and the lobes perhaps more 
ascending than in most of the species, middle-sized, 6.5 to 15 cm. in diameter, the 
upper surface commonly not so smooth and shining, but finely granular or even 
minutely downy, owing to the presence of scattered or more numerous trichomatic 
hyphe, sea-green, varying toward ashy or more commonly toward brownish, the lobes 
somewhat narrower, rounded with entire or undulate margins, beneath light-brown to 
blackish, but paler and sometimes white-foveolate toward the margin, larger rhizoids 
few or absent, and the surface scarcely veined but uniformly clothed with a dense 
nap; apothecia on extended lobes, middle-sized or larger, 3 to 7.5 mm. in diameter, 
orbicular, the disk brownish-black; hypothecium dark brown; hymenium pale brown 
below and darker above; paraphyses simple or rarely branched, commonly enlarged 
and brown toward the apex; asci cylindrico-clavate; spores 4 to 6-celled, 50 to 75 
long and 4 to 6 » wide. 
The plant has been found at Grand Marais, at Tower, and westward from Kettle 
Falls along the international boundary. On thin earth over rocks, 
Known in the White Mountains, the Rocky Mountains, and northward to Newfound- 
land and Greenland. Found in all of the grand divisions except Australia, 
7. Peltigera rufescens (Neck.) Hoffm. Deutsch. Fl. 2: 107. 1795. 
Lichen rufescens Neck. Meth. Muse. 79. 1771. 
Thallus closely adnate with ascending margins, scarcely middle-sized, 6 to 12.5 em. 
in diameter, the upper surface rather sparingly covered with trichomatic hyphe and 
downy or entirely devoid of them and smoother, the lobes more crowded and nar- 
rower than in the next with elevated and crisped margins, sea-green or more commonly 
becoming brown or reddish brown, beneath reticulated with brown veins, these 
more or less rhizoid-bearing, in ours the whole lower surface, except toward the 
margins, becoming dark brown; apothecia on extended lobes, middle-sized or larger, 
3.5 to 7.5 mm, in diameter, becoming vertical, oblong or revolute, the disk reddish 
brown varying toward blackish; hypothecium brown or brownish; hymenium com- 
monly pale brownish below and darker above; paraphyses simple or rarely brarched, 
@Nyl. Syn. Meth, Lich. 1: 325. 1858. 
