FINK—THE LICHENS OF MINNESOTA. 153 
5. Pannaria petersii Tuck. Gen. Lich. 54. 1872. 
Thallus squamulose-foliose, stellate, the lobes flat, clustered or scattered, radiately 
branched and many-cleft toward the circumference, frequently falling away at the 
center, olivaceous or black or rarely sea-green, the hypothallus absent, parenchym- 
atous throughout, the lobes scarcely more than 0.5 mm. wide and reaching 1.5 to 
3mm. in length; plant when of definite form about 15 to 40 mm. in diameter; apothecia 
sessile, without thalloid exciple (biatoroid), the disk black and flat with a thin, raised 
margin, minute, 0.2 to 0.5 mm. in diameter; hypothecium light brown; hymenium 
pale below and slightly purplish above; paraphyses simple or branched, commonly 
thickened and purplish toward the apex; asci clavate; spores simple and 2-celled, 
oblong and ellipsoid, hyaline or pale, 12 to 24 » long and 4 to 6 » wide. 
Collected on calcareous pebbles in the Leaf Hills in Ottertail County. The thallus 
was nearly obsolete, but the plant seems clearly to belong here. 
A strictly North American lichen, hitherto reported from New York, Alabama, 
Tennessee, and Iowa. 
6. Pannaria nigra (Huds.) Nyl. Not. Sallsk. Faun. Flor. Fenn. 5: 126. 1861. 
Lichen niger Huds. Fl. Angl. ed. 2: 524. 1778. 
Thallus composed of minute squamules, which are sometimes scattered but usually 
closely united into a more or less continuous granulose or coralloid crust, the slender 
lobes usually rounded, not exceeding 0.5 mm, in diameter, but sometimes branched 
and reaching 1 to 2 mm, in length in scattered conditions, lead-ashy in color, paren- 
chymatous throughout; plants irregular in form and covering patches 15 to 50 mm. or 
more in diameter, resting upon and bordered by a prominent blue black hypothallus; 
apothecia sessile, without thalloid margin, the disk commonly black or more rarely 
reddish brown, flat or convex with a thin, elevated margin, which frequently disap- 
pears, minute, 0.3 to 0.8 mm. in diameter; hypothecium light brown or darker; hyme- 
nium pale below, and brownish or purplish above; asci clavate; paraphyses simple 
or rarely branched, commonly enlarged and colored toward the apex; spores oblong, 
2 to 4-celled, 12 to 16 long and 4.5 to 7 » wide. 
Generally distributed in the State, but by no means common. On various rocks. 
The plant from Grand Portage referred to Pannaria flabellosa belongs here. 
Widely distributed in the United States and northward into British America and 
Alaska. Known in all the grand divisions. 
Family STICTACEAE. 
The family is represented in Minnesota by the genus Sticta, in which the algal sym- 
biont is Dactylococcus or Polycoccus, both blue-green alge, or the green Cystococcus. 
The thallus is large, plainly foliose, prostrate upon the substratum and well lobed. 
The cellular cortex is well developed above and below. Cyphelle are usually present 
and constitute the most marked characteristic of the family. The apothecia are 
borne upon the upper surface of the thallus, scattered promiscuously, or marginal or 
submarginal. They vary from adnate to subsessile. The spores are 2 to 4-celled and 
hyaline or brown. 
The relationship of the Stictaceae and the Pannariaceae was discussed under the 
latter family. As reasons for separating the Stictaceae from the Peltigeraceae follow- 
ing may be noted the general presence in the former of cyphellz and the different 
disposition of its apothecia. The presence may also be mentioned of upper and 
~ lower cortices in all the members of the former family and the absence of the lower 
cortex in most of the genera of the latter. 
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