16 



Bulletin 6 



summits of high hills or mountains, the orange becomes more 

 intense, almost approaching a red. So far as I know, no one 

 has ever investigated the ratio of chrysophanic acid presented 

 by plants from these diverse habitats, but it would prove an 

 interesting subject. Xanthoria is very closely related to that 

 section of the Caloplacaceae which shall include Caloplaca 

 elegans. Ten years ago, on a visit to Ragged Mountain, one 

 of the higher summits of Knox County, a solitary specimen 

 of Xanthoria pa?'ieti?ia was found on a rock at the summit. 

 Considerable search failed to discover another specimen. It 

 seemed desirable to me to leave the plant undisturbed and to 

 revisit the place at some future time to ascertain what would 

 become of it. It was seven years later before a second visit 

 was paid to the summit, and an amazing sight awaited. In 

 every direction from the rock originally the seat for that soli- 

 tary lichen, the plant had spread and there were hundreds 

 of individuals. Close investigation of the society revealed 

 another astonishing thing, and that the presence inextricably 

 mixed with the Xanthoria were fully as many individuals 

 of Caloplaca elegans. It was well-nigh impossible to distin- 

 guish between the two species in hand specimens. Alike 

 in color, in a general way in thallus, and absolutely in the 

 contents of the thecium, it seemed then, and I have not 

 changed my opinion since, that Caloplaca elegans is but an 

 anamorphosis of Xanthoria parietina. The establishment of 

 the Xanthoria on that mountain top has not as yet been sat- 

 isfactorily explained to my mind, and as a matter of fact the 

 distribution of the plant in our city streets is obscure. It 

 seems peculiarly to affect for its home the trunks of roadside 

 trees, and it is commonly noted that trees some distance back 

 from the road will support few or no examples of the plant 

 while the trunks of the roadside ones are covered. An obser- 

 vation some years since illustrated what might be called a 

 mode of vertical propagation for this species in a striking 

 way. Beneath a tree trunk, the surface of which supported 

 a host of individuals of the Xanthoria, there was a large 

 stone. This stone was covered with species and it was per- 

 fectly apparent that the coating had been derived from a 

 bringing down by water of fragments from the thalli above. 

 Five feet away from the first stone, which, by the way, leaned 



