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'we ourselves grow in our gardens plants from other parts of the 

 Dominion, as the beautiful British Columljian shrubs, the flowering 

 cuiTant {Rihes Sanguinea) and Sjringa, (Fhiladelphus Lewisii). These 

 lovely fehrubs, which are among the most conspicuous objects of our 

 gardens, are found on every hillside west of the Cascades in British 

 Columbia. From the same province, but considerably rarer, are two or 

 three species of Rhododendron. These conspicuous plants, however, do 

 not give the Botanist trouble, because their very beauty draws sufficient 

 attention to them for their whole history to be known — the difficulty is 

 with the inconspicuous ]>lants, such as creep in uninvited and unawares 

 among other seeds ; in fact what we call weeds. But what is a weed 1 

 "The dictionaries tell us," says Dr. Gray (Am. Jl. So. 3 S. xviii, p. 

 161), " any useless or troublesome plant." " Every plant which grows in 

 a field, other than that of which the seed has been (intentionally) sown," 

 says the Penny Cyclopedia. The Treasury of Botany defines it "any 

 plant which obtrusively occupies cultivated or dressed ground to the 

 exclusion or injury of some particular crop intended to be grown. 

 Thus even the most useful jjlants may become weeds if they appear out 

 of their proper place. The tei'ra is sometimes a[)plied to any insigni- 

 ficant-looking or unpi'ofitable plants which grow profusely in a state of 

 natui-e and also to any noxious or useless plant." Dr. Gray's own 

 definition is " plants which tend to take prevalent possession of soil 

 "used for num's purposes irrespective of his will." Of course in our list 

 of introduced plants those species are omitted which occupy ground in 

 a state of nature, but which also as weeds conspicuously intrude into culti- 

 vated fields, as Erigeron Cmiadeitse cmd A')nhrosia artemisioefolia peihaps 

 the most weedij looking plants we have. Some plants as Trifolimn repens 

 the white or Dutch clover, are truly useful when grown as crops, but 

 a great nuisance when they occur as weeds. Here, as in most of the 

 other parts of settled North America, a large jjroportion, in fact nearly 

 all, of the aggressive weeds are immigrants from Europe, and it may not 

 be amiss to consider shoi-tly the reason of this, for it is rather remark- 

 able that it should be the case. It is strange, too, that some wliich are 

 ■a great nuisance here as weeds, in their own country are not at all 

 plentiful, and the converse of this is also true; some species which in 

 Europe are most irrepressible are here hardly able to secure a foothold. 



