E. A. PEYOR BOTANICAL WOEK OF THE PAST SEASON. 73 



seemingly established itself in the borders of fields, where it has 

 been formerly introduced with the crop, and on railway banks. It 

 is strange that so conspicuous a plant should not have been noticed 

 before the present season. It is often accompanied by Bromus 

 arvensis, L., and B. comnmtatiis, Schrad. — the latter has usually 

 been held a native, the former as a mere casual ; but both, I think, 

 occupy an intermediate position between the truly indigenous B. 

 mollis, L. (almost ubiquitous in dry situations), or B. racemosus, 

 L. (confined with us to damp meadows in the lowlands), and a 

 grass of but a season's duration like their congener B. secaUnus, L., 

 which seems quite unable to obtain any permanent footing in the 

 soil. Bromus arvensis, of which a single stray specimen only 

 had previously been noticed in the county, I have seen quite 

 naturaKsed, to all appearance, by hedge-banks and on the sides of 

 fields, and that too in our own district. It is probably of much 

 more recent introduction than B. eommutatus, but both are likely 

 to make good their claim to the title of colonist. Plantago Timhali, 

 Jord., is perhaps not very uncommon amongst clover, but occurs 

 only where sown. Barkhaiisia taraxacifolia, DC, however, origi- 

 nally introduced with grass seeds, will probably be more per- 

 manent : it has been remarked in increasing quantity for the last 

 three or four years at Rush Green, near Hertford. Lepidium 

 Br aba, L., has also been observed in two widely separated locaKties, 

 and, from the great depth to which the roots run, is not unlikely 

 to become a troublesome weed, as it is almost impossible to eradicate 

 it. Both these last appear to be spreading rapidly in many parts 

 of the South of England. Lepidium ruderale, L., is another plant 

 in the same category. 



But it would be alike tedious and unprofitable to attempt any 

 complete account of the numerous exotics that have recently made 

 their appearance in the county. The following list of introduced 

 plants growing dui-ing the past summer on a siding by the rail- 

 way at Hatfield, where manure had been unloaded, will give some 

 idea of their number and variety. 



Fumaria densijlora, DC. Panicum miliaceum, L. 

 Sinapis nigra, L. ,, capillare, L. 



Camelina saliva, Crantz. Setaria viridis, P.B. 

 Linum usitatissimtmi, L. ,, glauca, P.B. 



Centaurea Cyanus, L. Phalaris canariensis, L. 



Echinospermum Lappula, Lehm. Agrostis Spica-Venti, L. 



Solanum Lycopersicum, L. Bromus secalinus, L. 

 Galeopsis latifolia, Hoffm. „ arvensis, L. 



Polygonum lapathifolium, L. Hordeum pratense, L. 



,, maculatum. Dyer. Secale cereale, L. 



Panicum Grus-Galli, L. Lolium italicum, A.Br. 



Amongst these, however, several usually indigenous species are 

 included. There is one point of view, indeed, from which some 

 importance is attaching to the first notice of these aliens : some 

 of them may very possibly become so far established, that in the 



