PELL/EA ATROPURPUREA. DARK PURPLE ROCK-BRAKE. 5 1 



limestone. In the first volume of the " Botanical Gazette," Dr. 

 J. Schenck says that it grows on a bare sandstone cliff in the 

 lower Wabash valley of Indiana, "though it is usually thouo-ht to 

 be found only on calcareous rock ; " and in the same magazine 

 Mr. H. E. Copeland says of some locations in Wisconsin: "It 

 grows as thrifty on the sandstone as when growing on calcareous 

 rocks in the southern part of the State." That the prevalent 

 opinion is erroneous is further confirmed by Mr. Williamson, 

 who in his " Ferns of Kentucky " remarks that " it is well dis- 

 tributed over the State wherever there are limestone cliffs, 

 though it is occasionally found in sandstone formations." 



It is interesting to notice how the knowledge of its geography 

 has progressed. It was known to Linnaeus as Pteris atropurpu- 

 rea, having been probably made known to Europeans by Clay- 

 ton, to whom it seemed so rare that he wrote to Gronovius that 

 he found it in "a shady place among the roots of red cedars at 

 Point-look-out, on the Rappahannock." This v;as previous to 

 the year 1 739. Michaux in the early part of the present century 

 gave it a wider range by the expression, " Rocks in the Alle- 

 ghanies." Beck in 1833 widened its range "from New York to 

 Carolina." In Sir John Franklin's voyage to the Arctic seas in 

 1819-22, it was found In these high regions, though it did not 

 attain there more than an inch or two in height. It has since 

 been found by Lyell in Greenland ; and, though it is not found 

 continuously, but in isolated spots, it has a wide geographical 

 range accorded to few other American Ferns. How nice it is in 

 its isolation may be gathered from a remark of Dr. Coulter in 

 the first volume of the " Botanical Gazette," who is describing it 

 as it grows near Hanover, in Indiana. He says : " The apparent 

 choice in the range of heights is very marked in the case of 

 Pellcsa aijvp2Lrp7trea, which is confined to a range on the topmost 

 rocks, litde if at all exceeding thirty feet in verdcal height." 

 From various sources we have accounts of its being found in 

 Texas, New Mexico, Arkansas, Colorado, and all through the 

 Rocky Mountains to arctic America. It does not seem to be 



