218 THE NATUEAL HISTORY RETIEW. 



and about our old retired villages. Most of tlie " colonists," op 

 weeds of cultivation, must have come over even with our earliest 

 importations of grain. The ornamental escapes from cultivation 

 established are comparatively few, but even among these scarcely 

 any can be fixed upon as belonging to our recent horticultural 

 importations. Whilst we have inundated many distant regions with 

 our own weeds and waste plants, no Japanese nor Califomian plant, 

 none from the extra- tropical regions of the southern hemisphere have 

 as yet sufficiently spread from our gardens, to be entered in any of 

 the lists of naturalized plants, and scarcely any as yet show any 

 tendency towards it. The only extra-European species which our 

 steady intercourse of three centuries has given us, are : 



On the seacoast, Spartina alternijlora, and possibly Senehiera 

 didyma. 



Along river banks and analogous waste places: Impatiensfulvay 

 (Enotliera biennis and Mimulus luteus ; to which may, perhaps, soon 

 be added EscTiscJioltzia californica. 



Along roadsides, railway banks, etc. : Erigeron canadense. 



As weeds of cultivation : Oxalis stricta, Claytonia per/oliata. 



In rivers and canals : Elodea canadensis. 



To these is added Gnaphalium margaritaceuiUy but we are unac- 

 quainted with the stations or circumstances in which it is found. 



The most remarkable of the above is the Elodea canadensis (Ana- 

 cTiaris ahinastrum, Bab.), of which the sudden appearance a few years 

 since, and the extraordinarily rapid dispersion without seeding (only 

 one sex being in the country) are so well kno^vn. None of the others 

 have taken so prominent a place in the spontaneous vegetation of the 

 country as the two Xanthiums and the two Amarantuses at Mont- 

 pellier. Even the Erigeron, which, with its enormous powers of Mgf^- 

 duction, infests whole districts on the Continent, remains very local 

 with us. It appears to propagate well ; we know of instances where 

 one or two plants one year have the following season covered a 

 considerable extent of railway embankment, but it has almost dis- 

 appeared again after a few years ; and long as it has been known 

 among us, it is not a common weed of the country. 



A few of our "colonists" from European sources maybe alto- 

 gether recent additions. Cuscuta epilinum is supposed to be among 

 the number. The Alfalfa clover, Trifolium hybridum has certainly 

 spread very much in some counties within the last few years, and 

 we believe that Galinsoga parvijlora, an American plant, but pro- 



