220 



Annals of Horticulture. 



signed to their introduction by reference to the catalogue of 

 Gillett, Gillett & Horsford, Woolson & Co., Kelsey, and others. 

 When the species has been in cultivation for many years, or 

 when it has been found to be impossible to assign any defi- 

 nite date, an asterisk has been used to denote that the species 

 has come into cultivation in this country. The dates of in- 

 troduction into England, or the dates of the first record of them 

 there, are taken entirely upon the authority of Nicholson' s Il- 

 lustrated Dictionary of Gardening. It will be seen that many 

 species which have appeared in England have never been in- 

 troduced into American trade. It does not follow, however, 

 that species are actually in cultivation in England because 

 they are recorded in this list. The record simply shows that 

 they were once introduced into England. Some of them have 

 never been known there outside botanic gardens and many of 

 them have been lost to cultivation. Many of the southern 

 species were introduced into England from the West Indies 

 or Mexico. The census may contain many errors and omis- 

 sions, but the difficulties of its preparation are almost insur- 

 mountable, and at most it is only preliminary to a more thor- 

 ough study of the subject at some future time. But no pains 

 has been spared to make it as reliable as our present knowl- 

 edge will permit. 



There are in North America, north of Mexico, about 10,150 

 known species of native plants, distributed in 1,555 genera 

 and 168 families. Of these, 2416 species are recorded in this 

 census, representing 769 genera* and 133 families. Of this 

 number, 1929 species are now offered for sale in America ; 1500 

 have been introduced into England, of which 487 are not in 

 cultivation in this country. In order to show the ratio of 

 cultivated species to those not yet introduced, the number of 

 species in each genus is given. 



* Excluding the hepaticaceous genus (and family) marchantia, the last one enumerated 

 in the census. 



Explanations. — An * denotes that the plant has been in cultivation in this country for 

 several or many years, or at least that the date of its introduction has not been de- 

 termined. 



Gill., Edward Gillett, Southwick, Mass. 



G. & H., Gillett & Horsford, Southwick, Mass. 



