Smithsonian [<• i 



Plate 1 1 



1. The hardy, coarse-textured fragrant shield-fern, Dryopteris fragrans (L.) Schott., is a 

 nearly ubiquitous inhabitant of sheltered ledges and crevices of rock outcrops in some 

 sectors of the Arctic and Subarctic, as for example Alaska. Characteristically, the shelter- 

 ing rocks are covered with crustose and flattened foliose lichens. 



licnen, is one 



2. The creamy white Cetraria cucullata (Bell.) Ach., an antler like fruticose 



of the many species of lichens that everywhere help to make up arctic tundra heaths. 

 (Slightly under natural size.) 



