FINK—THE LICHENS OF MINNESOTA. 217 
Distribution in the State the same as that of the species. On rocks. 
Occurs in Iowa, Missouri, Kansas, California,and eastern British America. Known 
also in Europe. 
TELOSCHISTES Norm. Nyt. Mag. Naturv. 7: 228. pl. 1. f. 4 a-g. 1853. 
PLATE 45, 
The thallus is usually foliose or subfruticose, a single species rising to a fairly good 
fruticose condition. In the foliose species the thallus shows a well developed cellular 
cortex above and below, and the space within is traversed by the loosely entwined 
medullary hyphe. The algal layer lies among the medullary hyphe just below the 
upper cortex, or in small thalli, especially in Teloschistes concolor, the algal cells may 
fill nearly all of the space between the medullary hyphee. In the more or less fruti- 
cose thallus of Teloschistes chrysopthalmus there is a marked tendency toward a radial 
arrangement of tissues in the erect lobes of the thallus. In these the algal layer is 
frequently developed on both sides of the compressed lobes inside of the pseudocortex, 
inclosing more or less medullary tissue. Rhizoids and cilia are more or less character- 
istic of all the species. The thallus lobes in the foliose species are usually short, but 
somewhat dissected, and commonly show a tendency to ascend at the margins. The 
prevailing color is yellow or orange, which manifests itself most commonly in the 
disks of the apothecia. The upper surface of the thallus usually shows the char- 
acteristic color also, but often varies toward gray or sea-green. The lower surface 
usually shows these paler colors with a tendency toward pale yellow. 
The apothecia are found more or less commonly in all of the species and may be 
terminal, marginal, or upon the upper surface of the thallus. The disk is commonly 
yellow or orange, and the margin is frequently ciliate. The hypothecium and hyme- 
nium are generally pale or slightly colored. The spores are of the polar 2-celled type, 
though this grades into an ordinary 2-celled condition even in a given species, while 
in one species admitted to the genus the numerous spores are constantly simple or of 
the ordinary 2-celled type. Aside from the single species, there are 8 spores in each 
ascus, 
In structure of the thallus the genus is close to Physcia, while in coloration and 
more especially in spore characters the relation with Placodium is close. Teloschistes 
is no doubt more closely related to the latter genus. 
Five species and subspecies occur in the State. On trees, old wood, and rocks. 
Type species Teloschistes flavicans (Sw.) Norm. loc. cit. 
EXPLANATION OF PLATE 45.—Fig. 1, the plant, showing the branching fruticose thallus and the 
apothecia. Fig. 2, a portion of thallus and three apothecia. Fig. 3, a section of an apothecium and the 
thallus below; a, the hymenium; b, the hypothecium; c, the fungal hyphe; d, the algal cells; ¢, the 
pseudocortex of entangled hyphe. Fig. 4, a longitudinal section of the thallus; @ and d, the pseudocor- 
tex of hyphae; 6, the better developed algal layer of the upper side of the ascending branch; c, the 
medullary layer. Fig. 5, paraphyses and an ascus. Fig. 6, free polar 2-celled spores. Fig. 1, natural 
size; fig. 2, enlarged about 8 diameters; figs. 3, 4, enlarged 400 diameters; figs. 5, 6, enlarged 650 diameters. 
From Schneider. 
KEY TO THE SPECIES. 
Thallus subfruticose, erect, spreading, or subpendent. . . - - 1. T. chrysopthalmus. 
Thallus foliose. 
Thallus lobes reduced to granulose-margined squamules, 
or the whole thallus reduced to a greenish-yellow, 
powdery crust............2.22.2000002---2-0-0020----- da. T. concolor effusus. 
Thallus lobes well developed. 
Margins of the lobes or the whole lobes ascendant; 
margins isidioid-granulose............-.-------- 3. T. lychneus. 
7920—10-—-—15 
