340 HARPER 



Dicerandra Benth. (Ceranthera Ell. 182 1). 



Actinospermum Ell. 1823. 



Lygodesmia Don 1829. 



Warea Nutt. 1834. 



Macranthera Torr. (Conradia Nutt. 1834). 



Siphonychia T. & G. 1838. 



Thysanella Gray 1845. 



Phoradendron Nutt. 1848. 



Gibbesia Small 1898. 



Aldenella Greene 1900. 

 Sophronanthe (Benth. 1836), and perhaps one or two other 

 genera, were based on species discovered in the 19th century 

 but now include some of Michaux's or earlier species. 



The middle curve in the first diagram is based on the dates of 

 original description of our woody plants, and the lowest one 

 gives the same data for trees alone, so the distance between the 

 two curves corresponds to the number of shrubs. These show 

 that just about one-third of our trees and shrubs were known 

 to Linnaeus, and that very few new ones have been described 

 since the time of Elliott. 



The second diagram is for all our species of vascular plants 

 whose bibliographic history is known, about 700 in number. 

 The upper curve represents original descriptions, as in the first 

 diagram, and the lower is compiled from the dates on which the 

 same species received their present names. 



We see from this diagram that not quite one-fourth of our 

 species were known to Linnaeus (how many of these were 

 originally described by him and how many by earlier authors I 

 have not attempted to show), and that more than half of the 

 whole number were unknown at the beginning of the 19th 

 century. Michaux is the authority for more of them than 

 any one else since Linnseus, having described over 100, or 

 something like 14% of the whole. Walter is a close second, 

 with 13% credited to him. It will be noticed also that more 

 of our species have been described in the last fifteen years than 

 in fifty years previous to that, and as many in the last ten years 

 as in forty years previously. This is due partly to the narrowing 

 conception of species and partly to the activity of Dr. Small 

 and his contemporaries in field work. 



The lower curve shows that over 14% of our plants still bear 



