338 HARPER 



the Pacific coast, or if they do their identity or indigeneity in 



those parts is doubtful. 



The following species and varieties, none of which seem to be 



very rare (each having. been found in at least three counties), 



are not certainly known outside of the Altamaha Grit region. 



Mesadenia lanceolata virescens Harper 

 Marshallia ramosa Beadle & Boynton 

 Pentstemon dissectus Ell. 

 Polygonella Croomii Chapm. 

 Rhynchospora solitaria Harper 

 Sporobolus teretifolius Harper 



An equal number are known in the upper or lower thirds of 



the coastal plain, but have not yet been reported in any other 



state, viz. 



Baldwinia atropurpurea Harper 

 Dicerandra odoratissima Harper 

 Zizia arenicola Rose 

 Viola denticulosa Pollard 

 Nymphgea fluviatilis Harper 

 Eriocaulon lineare Small 



The following, founded on material from the Altamaha Grit 



region, are now known in other states. 



Sabbatia gentianoides Ell. 

 Polygala Harperi Small 

 Arenaria brevifolia Nutt. 

 Siphonychia pauciflora Small 

 Juncus scirpoides compositus Harper 



Bibliographic History. 



Finally, the bibliographic history of the flora of the Altamaha 

 Grit region since the time of Linnaeus' Species Plantarum may 

 be summarized very expeditiously by means of a couple of 

 diagrams. These, like most of the foregoing statistics, refer 

 to Avascular plants only, the cellular cryptogams being omitted 

 from the calculations for the reasons given on page 313. 



In the first diagram the uppermost curve represents graphi- 

 cally the dates of description of our genera, beginning with 1753. 

 The abscissas represent dates, as indicated at the base of the 

 diagram, while the ordinates represent the number of genera 

 which had been published up to any given date. In cases 

 where the name originally given to a genus has been changed 

 for any reason, only the original date is taken into consideration. 



The curve for genera suggests the following points of interest. 

 Just about half of our genera were known to Linnaeus, doubtless 



