68 
H. O. JUEL 
Another English physician residing in Virginia, J. Mitchell, 
also collected plants and sent descriptions of them to Europe. 
In 1748 he published a paper in the Acta naturae curiosorum 
on the principles of natural history and in an appendix he gives 
the floral characters of 30 new genera of plants. No species 
are mentioned, and most of his generic names were replaced 
later by other ones. 
We now have to return to Linnaeus. The dissertation 
» Plantse Martino-Burserianae» was published in 1745. Here we 
find only such American species as Burserus had received from 
an apothecary in Paris, and of which I have spoken above. In 
this paper they are still taken as coming from Brazil. 
In the same year appeared the dissertation »Hortus Upsa- 
liensis». Here is given a description of the botanical garden, 
which had then been under Linnaeus’ direction for three years. 
Through his care and with the help of a very skilful chief gar¬ 
dener, D. Nietzel, who had been Clifford’s gardener when 
Linnaeus stayed in Hartecamp, the botanical garden had deve¬ 
loped considerably and the number of foreign plants was much 
increased. In this dissertation there are lists of the genera cub 
tivated in the different parts of the garden, and among these we 
find many of North American origin. One of these parts, the 
»area autumnalis», contained species which were somewhat deli¬ 
cate and needed some protection from the cold and which were 
late in producing flowers. Most of these were North American, 
such as species of Aster, Eupatorium, Helenium, Rudbeckia, 
Silphium, Monarda, etc. 
A more complete account of the plants cultivated in the 
garden was given by Linnaeus in his book »Hortus Upsaliensis», 
issued in 1748. The number of North American species contai¬ 
ned in this book is relatively large, amounting to over 200. In 
the preface he mentions having received such species for the 
garden from Gronovius, Collinson, Catesby and Lawson. His 
interest in aquiring N. American plants for the garden seems to 
have been great. In a later catalogue of the garden, contained 
in the dissertation »Demonstrationes plantarum» of 1753, the 
