FINK—THE LICHENS OF MINNESOTA. 55d 
Also generally distributed throughout North America, and cosmopolitan in its 
foreign distribution. 
EXPLANATION OF PLATE 2.—A, Plant of Graphis scripta on balsam fir, showing the elongated and 
variously curved apothecia and the whitish coloration due to the thallus. B, Plants of Arthonia radiata 
on balsam fir, showing the irregular apothecia and the whitish coloration due to the thallus. A en- 
larged 13 diameters; B enlarged 1% diameters. 
la. Graphis scripta recta Nyl. Not. Sillsk. Faun. Flor. Fenn. 5: 252. 1861. 
Apothecia straight and parallel or nearly so, in ours longer and often reaching 
5 to 10 mm. in length; in ours also the epiphlceodal portion of the thallus, including 
the thalloid exciple, wanting, so that there appears to be no thallus. 
It seems probable that this form might better have retained the status of a species. 
Throughout the northern portion of the State. On birches. 
Distributed throughout the northern part of the United States and British America. 
Known also in Europe and Asia. 
1b. Graphis scripta serpentina (Ach.) Nyl. Not. Sallsk. Faun. Flor. Fenn. 5: 252. 
1861. 
Lichen serpentinus Ach, Lich, Suec. 26, 1798, 
The epiphloeodal portion of the thallus unusually well developed, whitish and 
immersing the apothecia, and usually occurring in rather small areas upon the sub- 
stratum. 
Generally distributed over the State. On trees. 
It is not possible to state the North American distribution of this subspecies, as it 
has been generally misunderstood. Our subspecies limitata of the preliminary 
reports undoubtedly belongs here, as the limiting dark line isalmost uniformly wanting. 
Doubtless also the large number of specimens from British America called subspecies 
limitata are the present subspecies. 
Known in all the grand divisions except Africa. 
2. Graphis dendritica Ach. Lich. Univ. 271. pl. 3. f. 16. 1810. 
Opegrapha dendritica Ach. Meth. Lich. 31. pl. 1. f. 10. 1803. 
Thallus largely hypophloeodal, and the epiphlceodal film much as in the last species; 
apothecia. more commonly immersed in the substratum and copiously radiate- 
branched, or in the less developed forms clustered, the cluster forming the radiate 
arrangement, and the individual apothecium less branched, the disk and proper 
exciple much as in the last species, but the thalloid veil rather less frequently pres- 
ent; internal characters also as in the last, but the spores shorter, containing fewer 
cells, and becoming colored and even dark-colored with age (4 to 8-celled, and 20 
to 36 » long and 5 to 8 » wide). 
Some of the material referred to Graphis scripta limitata in the preliminary reports 
may belong here, but a plant from Spicer County determined by Mr. W. W. Calkins 
appears much nearer this species externally. The spores of the latter, however, 
occasionally reach 10-celled conditions and they show only an occasional trace of 
color. On the other hand, a plant collected at Beaudette and less well marked 
externally shows the shorter, fewer-celled spores. Similar specimens have been 
collected in Illinois, Iowa, and Nebraska, but none of these northern plants are so 
well marked as those from the South, and it may well be doubted whether the species 
really occurs in any of these States. 
Widely distributed in the Southern States and occurring all along our Atlantic 
coast. Also in Europe, Asia, and South America. 
ARTHONIA Ach. Neu. Journ. Bot. Schrad. 1%: 3. pl. 4. 1806.- 
The thallus is rudimentary in structure and never shows any indication of cortical 
tissues. It is hypophleeodal in its early development and remains at least partly so 
in a large number of species. Under the best conditions it may become crustose and 
