102 Rhodora [June 



by the Merrimat' River near Newburyport, Massachusetts, indicating 

 that the plant has possibly washed down from some unverified station 

 at the headwaters of the Merrimac. 



Outside this very restrictetl area Paronychia is unknown in tiie 

 Northern States. Since its discovery in Crawford Notch in 1843, it 

 has, however, been supposed to be identical with the plant of the 

 South described by Michaux as Atii/chia argyrocoma, "in rupibus 

 montium superioris Carolinae," ^ and afterward taken up by Nuttall 

 as Paronychia argyrocoma and stated to grow "on rocks, in the moun- 

 tains of upper Carolina, and on the banks of French Broad river, in 

 Tennessee, near the thermal springs." ^ Subsequently the plant of 

 the South has been found at various mountain-stations of North 

 Carolina and Tennessee, locally south in the mountains of Georgia, 

 and north to the Peaks of Otter in western Virginia. 



In the region between the Blue Ridge of Virginia and the White 

 Mountains of New Hampshire Paronychia argyrocoma is unknown 

 (save at the small isolated station near Newburyport) ; yet, as already 

 implied, the plant of the South is as characteristic of many dry summits 

 and slopes at the southern extremity of the Appalachian system as is 

 its northern representative in the Wiiite Mountains. North of the 

 White ^Mountains the ])lant is quite unknown, nor does it occur in 

 the j)olar regions. In fact, the genus Paronychia does not belong to 

 the arctic flora which we find so generally represented on the ex[)osed 

 slopes of the AVhite Mountains; instead, it is a genus confined pri- 

 marily to the warmer tem))erate regions, in North Ameriea thirteen 

 species occurring south of latitude 3.5°, and only one as far north as 

 New England. 



This very evident affinity of a typical ])lant of the naked slopes of 

 the W' hite Mountains with a distinctly southern flora is, so far as known 

 to the writer, (piite without parallel. In many cases typical White 

 Mountain ])lants are also known at the highest altitudes in the Southern 

 States, as for instance Armaria grocniandica, Lycopodium Srlago, 

 Potenti/la frideniata, and Pyrus americana above 6000 feet on Roan 

 ^lountain. North Carolina; but in northern New England and 

 adjacent Canada these plants are often as abundant at sea-level as at 

 high altitudes, and in their broad range they occur extensively in polar 



1 Michx.. Fl. i. 114 (1803). j 



-Null., Gen. i. 160 (1818). 



