54 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Collected once at Emo along the northern boundary. On Peltigera aphthosa. 
A North American lichen known elsewhere at New Bediord, Massachusetts, and 
at Fayette, Iowa. 
GRAPHIS Adans. Fam. Pl. 2: 11. 1763. 
The thallus is similar to that of Opegrapha, being hypophloodal in part and devoid 
of differentiation into layers. A thin epiphloodal portion usually spreads over the 
substratum as a film, The algal symbiont is, as usual in the family, similar to that 
of Opegrapha. 
The apothecia are linear, usually curved, and not infrequent] y more or less branched, 
shorter and even suborbicular forms occurring rather rarely. They may be immersed 
in the substratum completely or only slightly. The proper exciple is dark and per- 
haps most commonly black, at least above, and is usually crowned by a portion of the 
epiphloeodal thallus film, which may be regarded as a thalloid exciple. The disk is 
closed or narrowly linear and commonly black. The spores are usually composed of 
6 or more cells, though 4-celled forms occur, and even muriform-spored lichens are 
included in the genus by lichenists. In form the spores are commonly oblong- 
ellipsoid, and the exosporium is often wavy, giving the spore a sort of caterpillar-like 
form. Both hyaline and more or less brownish spores occur within the genus. 
The similarity between Graphis and Opegrapha is apparent enough, and the present 
genus seems also to show a somewhat close relationship with such genera as Conotrema 
and Megalospora, where we find similar spores and more or less evanescent thalloid 
exciples surrounding the proper exciples. 
Mr. W. W. Calkins has recognized four species within the State, but two of these 
are plainly the common Graphis scripta, and a third perhaps another form of the same 
species. Ours all occur on trees, 
Type species Lichen scriptus LL. (Graphis scripta (L.) Ach.) 
Based on Lichenoides Dill. Muse. pl. 18. f. 1, 2. 1741, figure 1, being identified in 
L. Sp. PL. 1140. 1753. 
KEY TO THE SPECIES. 
Epiphloodal portion of the thallus rather thick, not widely 
spread... 2... eee eee Ib. G. scripta serpentina. 
Epiphloodal portion of the thallus thin, usually widely 
spread. 
Apothecia radiately branched or radiately arranged... 2. G. dendritica. 
Apothecia not radiately branched nor radiately arranged. 
Apothecia variously curved, sometimes branched. 1. G. scripta. 
Apothecia straight and parallel........2..2....... la. G. scripta recta. 
1. Graphis scripta (L.) Ach. Lich. Univ. 265. 1810. PuLatve 2, A. 
Lichen scriptus LL. Sp. Pl. 1140. 1753. 
Thallus commonly showing plainly as a smooth, thin, whitish, ashy, or more rarely 
somewhat olivaceous crust, this either limited or widely spread over the sub- 
stratum; apothecia usually much elongated, variously curved, sometimes branched, 
about 0.2 mm, in width and often 3 mm. or more in length, more or less superficial, 
the disk linear and appearing as a closed and often pruinose furrow, the proper exciple 
commonly veiled by the thin thalloid one; hypothecium dark brown; hymenium 
pale or pale brownish; paraphyses simple or rarely branched, frequently enlarged 
and darkened toward the apex; asci clavate or cylindrico-clavate; spores hyaline, 
oblong to linear with rounded ends, the exosporium wavy, usually 7 to 10-celled, 20 
to 40 » long and 7 to 9.5 » wide. 
Generally distributed over the State. On trees. 
