﻿iv Proceedings. {October 4th, 1904.. 



The genus Sisymbrium, apart from the aboriginal species 

 admitted in the British flora, is manifesting a predilection for 

 Lancashire and Cheshire, if we may judge from its attempts at 

 colonisation, in recent years, by one or other of its species. 

 S. polyceratium, L., has long been a constituent of the Cheshire 

 flora at Birkenhead and Egremont ; S. pannonicum, Jacq., 

 recently noticed in the Society's Memoirs (Vol. 47, Part I., 1902), 

 is naturalised at St. Anne's-on-the-Sea, Fleetwood, Preston, 

 Crosby, Blundellsands, and elsewhere ; and now a third species, 

 S. strictissimum, L., has to be chronicled as having secured a 

 foothold near Manchester. 



Some examples of the last-named plant, from Heaton Mersey, 

 were sent me for naming, six weeks ago, by an ardent Stockport 

 botanist, Mr. Jas. E. McDonald, who is doing excellent work in 

 tracing the life-histories of some of our common British plants, 

 and whose papers on Ranunculus Ficaria (Naturalists' Journal, 

 Nov., 1902, p. 187), and Adoxa Moschatellina (Nature Study, 

 Sept., 1904, p. 189), are admirable types of painstaking investi- 

 gation. 



Sisymbrium strictissimum occurs on the Lancashire side 01 

 the Mersey, in the grounds surrounding the works of Messrs. 

 Melland and Coward, Ltd., manufacturers, bleachers, and dyers, 

 of Vale Road, Heaton Mersey ; this firm, through their Mr. E. A. 

 Russell, has been most obliging in granting ready access to its 

 grounds. 



Mr. McDonald first noticed it at this station five or six years 

 ago, and it has not only held its own amidst the other vegetation, 

 but has steadily increased its area. The plant was first observed 

 many years ago as growing outside the boundaries of the bleach- 

 works, on the Stockport side, but last summer Mr. McDonald 

 noticed it from the opposite bank of the Mersey, growing on a waste 

 heap on the west side of the bleach-works, its rich yellow corymbose 

 flowering spikes making it sufficiently conspicuous in the mass. 

 Mr. McDonald tells me that several Stockport botanists, besides 

 himself, without being able to ascertain its name, have had the 

 plant under their observation for many years, and have gathered 



