ECOLOGY OF ISLE ROYALE. 227 



the Northern States and Canada, 1898. The report of the expedition 

 for 1904 followed the nomenclature of Britton's Manual of the Flora 

 of Northern United States and Canada, 1901. 



II. Annotated List of Plants. 



Lichens. 



By lichen zone No. 1 is meant to include the crustaceous lichens; 

 these forming small x>atches on the rocks as in Placodium elegans, in 

 which the thallus is principally imbedded in the rock so closely that 

 the rock must be broken away to secure them. Zone No. 2 (Foliose 

 zone) includes the flat thallus species which are attached by rhizoids, 

 as Parmclia. These can be scraped or pulled off. Zone No. 3 (Fruiti- 

 cose zone) includes the upright lichens like Cladonia. 



1. Ramalina calicaris farinacea (C) Fr. Vertical rock cliffs at 

 water's elge. Principal branching lichen on vertical cliffs. Common 

 Sta. I, Sub. 1. 



2. Cctraria lactinosa Ach. On nearly bare surface of rocks Sis- 

 kowit Bay, (V, 2). Occasional. 



3. Evernia prnn-astris (C) Arch. A light green, branching form 

 growing in Cladonia zone (I, 1). 



4. ZJsnea barhata cerotina (Ach.) Schaer. Hanging from trees along 

 Siskowit cabin trail (V, 4), also on trees at Rock Harbor (I, 3). Com- 

 iiion. 



f). Usnea longissima Ach. A pendulous form 12-15 inches or more 

 in length. Occurs on conifers. T^ess common than preceding species. 



C>. Parmelia perlata (Jacq.) Ach. Top of cliff at Rock Harbor (E, 

 2). Not widely distributed. 



7. Parmelia sasoitalis sulcata Tayl. A gray foliose form growing on 

 ven- thin black humus on sloping tops of cliffs. Noted to be abundant 

 top of rock cliff at Rock Harbor (I, 1). 



8. Parmelia eaperata (C) Ach. On rocks of foliose lichen zone at 

 Rock Harbor, I, 1; V, 2. 



9. Parmelia eonspersa Ehr. One of the most common lichens on 

 the island, and the principal form in the second (foliose) lichen zone of 

 the sloping rock shore. Also fairly abundant on rock surfaces back 

 from the shore. I, 1; V, 2; V, 3;"l, 2. 



10. Physcia pulverulenta (Scrieb.) Nyl. Natural openings on bed 

 Tock, growing on very thin hard humus. V, 3. 



11. Oyrophora hyperiorea Ach. On almost bare rock in the foliose 

 lichen zone (No. 2). Scarce. V, 2. 



12. Gyrophora [Vmbilicaria) vellea (C) Ach. Occurs in patches 

 on vertical rock faces. I, 1. Fairly common. 



13. Sticta pulmonaria (C) Schaer. Common along Siskowit cabin 

 trail, on trunks of fallen trees. Fairly common in similar places else- 

 where in forest. V, 4; IT. 



14. Peltidea (Peltigera) aphthosa (L) Ach. In forest along cabin 

 trail to bog at Siskowit Bay. Fairly abundant (V, 4). 



15. Peltigera canine (C) Hoffm. On moist moss patches in woods, 

 and in shady places. Common. V, 4. 



16. Placodium elegans (Link) DC. On exposed rock surfaces along 



