— go- 



lf they are dry they are very brittle, and must be well dampened before be- 

 ing put in the press. When moistened the Umbilicarias are deep green, or 

 olive-green, becoming dark gray, brown or black when dry. 



The economic uses of Umbilicaria are of some importance ; several 

 species yield a useful dye. Linnaeus says " some of them are superior in 

 nutritive qualities to the ' Iceland Moss.' " They contain a bitter purgative 

 quality which makes the use of them for food unwise. 



Umbilicaria cylindrica (L.) Delis. Thallus many leaved with round 

 lobes, smooth and of medium size. The color is bluish or smoke-colored 

 gray, the margin is thickly fringed with black fibrils, giving the 

 plant a very attractive appearance. Beneath, the thallus is a pale brown, 

 usually smooth, but some specimens have soft fibrils. The apothecia 

 are medium, at first sessile but as they mature are elevated; they are 

 sooty-black, orbicular, plicate or composed of tiny folds. This pretty 

 lichen is found on alpine rocks, both in this country and Europe. In- 

 Labrador and Newfoundland it is common and usually fertile. 



Umbilicaria probcscidea (L.) Stenh. Thallus one-leaved, flat and 

 rather thin, with few lobes, which are crenate : it is rugose above, especially 

 at the centre. In color it is blackish brown, turning blue-gray at the centre. 

 Beneath, the thallus is smooth, naked and pale gray or pruinose ; it is closely 

 appressed to the substratum and is somewhat rigid and brittle. It is gener- 

 ally fertile, with numerous, small apothecia which are round. 



Umbilicaria flocculosa Hoffm. The thallus is dark-brown in this 

 species, with a rough, sooty appearance, is medium, one-leaved, thin 

 with a scalloped margin. Some specimens are slightly papulose or squamu- 

 lose, reflexed at the margin. Beneath, the thallus is lighter in color, more or 

 less reticulated, especially at the center; it has no fibrils. The apothecia are 

 small, flat and sessile, more numerous toward the margin of the thallus. 

 Found on high mountains in North America, as well as in Europe. 



Umbilicaria hyperborea Hoffm. Thallus usually one-leaved with 

 jagged edges, rugose and occasionally perforate; in color brownish- black. 

 Beneath, the thallus is dark brown, usually smooth, but some specimens are 

 slightly pitted. The apothecia are small, oblong and plicate, with a flat, 

 black disk. This lichen is found on rocks on high mountains and varies a 

 good deal according to age ; is common in the Rocky Mountains. The speci* 

 mens are always small, and quite free from the substratum except at the 

 one point of attachment. 



Umbilicaria ph^a Tuckm. Thallus small or medium, one-leaved and 

 smooth, especially toward the centre; it is reddish-brown with few lobes and 

 uneven edges. Beneath the thallus is a pale brown, growing darker with 

 age ; it is very granulate except at the margin where it is usually smooth, 

 has no fibrils. The apothecia are small and sunken in the thallus; they are 

 very numerous especially near the margin. Found on rocks of the Pacific 

 Coast and in the Rocky Mountains. 



Umbilicaria erosa (Web.) Hoffm. Thallus medium in size, one-leaved, 

 with few rounded lobes, which are filled with cracks, the edges are ragged, 



