WEEDS AND THETK CHARACTERISTICS. 297 
live of origin or appearance, occurring* in cultivated ground, in addi- 
tion to, and, therefore, more or less interfering with and injurious to 
the crop intended to be grown. This is the idea of a weed in the 
mind of horticulturists and farmers, and as it is sufficiently definite to 
be scientifically employed, there does not seem to be any special benefit 
arising from a restricted botanical use of it, such as that advocated by 
Dr. Seemann. 
The leading characteristic of a weed, in this extended sense, is that 
of being out of place, and it is this point that is generally referred to 
in vague dictionary-definitions of the word. 
Though it is the fact that plants are weeds only on ground employed 
by man for the artificial growth of definite species, yet it does not 
follow that all weeds must be necessarily exotic species. To take 
this country, with which I am chiefly familiar, and which is, in 
all respects, an excellent field for the study of weeds, — although 
there must always exist widely-different views as to the nativity or 
otherwise of a large number, yet with regard to some I am not 
aware that any British botanist has expressed his disbelief in their 
truly indigenous growth. Ononis arvensis. Tussilago Farfara, and Eu- 
phrasia Odontites, are examples. They are certainly weeds, and very 
troublesome ones, and also, we must believe, in the absence of any kind 
of evidence to the contrary, natives of this country. S'tlene inflata, Stel- 
foria media, and Veronica hederifolia, seem to stand in the same cate- 
gory. There is no difficulty in supposing that such species have be- 
come weeds since the origin of cultivation, and as a result of it; that, 
i" fact, the conditions set up by agriculture and gardening liave fur- 
nished numerous localities highly favourable to their growth. "What I 
mean to affirm is, that a plant is a weed only in virtue of its situation ; 
it may be an ornamental or eveu a useful plant in its place, but out 
°f that place it becomes a weed. A Sunflower in a field of turnips is 
»s much a weed as Brassica Napusin a flower-garden, but reverse their 
situations and the term is inapplicable to either. So when waste land, 
such as a heath, is enclosed and brought under cultivation, the species 
composing its original flora become weeds in the new fields. 
With regard to the term " weedy." It is no doubt true, that many 
°f the common weeds of cultivation have characters such as those in- 
dicated by Dr. Seemann, as implied in this term, but there are many 
othns (as the first triplet of plants mentioned above) which are just 
