WEEDS. 
107 
round the world. The shepherd's-purse, with others, is com- 
mon in China, on the most eastern coast of Asia. One kind of 
mallows belongs to the East Indies ; another to the coast of 
the Mediterranean. The gimson weed, or Datm^a, is an Abys- 
sinian plant, and the Nicandra came from Peru. It is supposed 
that the amaranths or greenweeds, so very common here, have 
also been introduced, though possibly only from the more south- 
ern parts of our own country. 
Some few American plants have been also carried to Europe, 
where they have become naturalized ; but the number is very small. 
The evening primrose, and the silkweed, among others, have 
sowed themselves in some parts of the Old World, transported, 
no doubt, with the tobacco, and maize, and potato, which are 
now so widely diffused over the Eastern continent, to the very 
heart of Asia. But even at home, on our own soil, the amount of 
native weeds is small when compared with the throngs brought 
from the Old World. The wild cucumber, a very troublesome 
plant, the great white convolvolus, the dodder, the field sorrel, 
the pokeweed, the silkweed, with one or two plantains and thistles, 
of the rarer kinds, are among the most important of those whose 
origin is clearly settled as belonging to this continent. It is also 
singular that among those tribes which are of a divided nature, 
some being natives, others introduced, the last are generally the 
most numerous ; for instance, the native chickweeds, and plan- 
tains, and thistles, are less common here than the European 
varieties. 
There are other naturalized plants frequent in neglected spots, 
about farm-houses, and along road-sides, which have already" be- 
come so common as to be weeds ; the simples and medicinal herbs. 
