PLANTS OF MONROE COUNTY. 



Introduction of Species. 



As our territory is traversed by a number of railroads, new 

 plants are constantly being introduced. Many of these new intro- 

 ductions are from the West. 



At the time of the publication of the original list of plants, in the 

 summer of 1896, the Russian Thistle (Sa/so/a Kali tenuifolia) hfid 

 not been found in this vicinity. Its arrival, however, was confidently 

 expected, and a close watch was kept, with the result that it was soon 

 observed by Dr. Booth along the tracks of the New York Central 

 railroad. Now it has spread to many parts of the county. The 

 rapidity with which it increases and takes possession of the land was 

 particularly noted last summer. A short branch of the Pennsylvania 

 railroad was built about two years ago from Scottsville to Garbutt, 

 through a section where the Russian Thistle was absolutely unknown. 

 Now the roadbed is thickly lined with this immigrant from western fields. 



A number of plants which were noted as rare or scarce in the 

 list of 1896, are now abundant in many localities. Among these may 

 be mentioned the following : 



Nasturtium sylvcstrc is plentiful along the flood plain of the 

 Genesee river for many miles south of Rochester ; Trifoliiim pi-ocum- 

 bens is now frequently found ; Potentilla recta has so increased as to 

 be very plentiful along roadsides, particularly in the southern part of 

 Monroe county ; Hicraciurn aurantiacum is now a pernicious weed in 

 many places ; Sonchns arvcnsis has spread over a large territory, and 

 is constantly being reported in new localities ; Lysimaciiia nuinniularia 

 is plentiful in lawns in Rochester and vicinity, and along Oatka creek, 

 in Scottsville, is growing like a weed, in company \yith Myosotis palus- 

 tris ; Vincetoxicj(77i nigrum has spread rapidly in the southern part of 

 Rochester, and has been reported in other parts of the county ; 

 Chenopodiinn Botrys is frequently found along the New York Central 

 railroad in Rochester and in adjoining towns. A few specimens of 

 Sisymbrium altissimum were first found in Rochester about two years 

 ago ; now the plant is growing plentifully in many parts of the city 

 and adjacent towns. 



Recently Described Species. 



Although it had been noticed by' our botanists that many of the 

 specimens of Crataegus found in and around Rochester did not 



