766 



fers too materially in aspect not to excite special attention. I cannot 

 find any allusion to P. dumetorum as a British species in the writ- 

 ings of Ray, Gerarde, or other old English botanists, and it is a re- 

 markable fact that Linnaeus was ignorant of its existence in Sweden, 

 although it appears from Wahlenberg, Fries and others to be no rare 

 plant in that country, even in the vicinity of Upsal, where Linnaeus 

 taught and resided, and was in the habit of making herborizing ex- 

 cursions with his pupils, accompanied by the acute German botanist 

 Ehrhart. Yet Linnaeus knew the plant well, and imposed the specific 

 name of dumetorum upon it in the second edition at least of the 

 ' Species Plantarum' (for I have not the first by me to consult), only 

 seven years after the publication of the improved edition of his 'Flora 

 Suecica' in 1755, wherein no mention is made of the plant even as a 

 remarkable variety. Wikstrom (Stockholm's Flora, p. 282) tells us it 

 was first noticed as a Swedish plant in the province of Halland, and 

 published as such by Dr. Osbeck, in his ' Flora Hallandica,' printed 

 in the Swedish Royal Society's Transactions for 1788, some years 

 after the death of Linnaeus, and consequently when the species was 

 generally known and distinguished from P. Convolvulus and its winged 

 variety. Yet Wikstrom himself gives many stations for it in his ex- 

 cellent flora of the country one (Swedish) mile round Stockholm. 

 Facts like these are curious, as attesting the slow advances of the hu- 

 man mind in discovery, even when dependent on the simple exercise 

 of the senses, involving no process of inductive reasoning or laborious 

 research. Impulses arise, we scarcely know how, at distant and in- 

 determinate epochs, the spirit of inquiry is aroused and pervades the 

 nations, when discoveries of all kinds, natural, moral, and political, 

 crowd thick and fast upon us. The high latitude attained by P. du- 

 metorum on the continent of Europe, even along the western coasts, 

 renders it probable that it will eventually prove indigenous to the 

 greater part of Britain. 



The American P. scandens, now referred by my friend Dr. Gray to 

 P. dumetorum of Europe, of which it is possibly only a form, certainly 

 presents some striking and permanent differences in the much more 

 robust growth of its very long, twining stems, which are usually 

 strongly tinged all over with purple ; in the broader, shorter, less 

 acuminate leaves, that approach more to cordate and less to hastate 

 or sagittate than in ours, the lobes being more rounded ; in the ra- 

 cemes, which are notably less elongated in the American plant, and are 

 usually interspersed with several small but conspicuous leaves, where- 

 as in P. dumetorum the racemes are naked, or very nearly so, the 



