126 EQUIS.ETACE.SJ. 



ORDER CX. OPHIOGLOSSACE.E. (ADDER'S TONGUE TRIBE.) 



OPHIOGLOSSUM. (Adder's Tongue.} 



I. O. vulgatum. L. (Common Adder's Tongue.) 



Moist pastures. 5, 6. 



Football Field, Harrow ; and abundant in a field at 

 Greenford. (Edition i.) Roxeth ; Pinner Hill. Ruislip 

 Moor. (Flor. Midd.) 



ORDER CXIII. EQUIS^ETACE^E. (HORSETAIL.) 



EQUISETUM. (Horsetail] 



1. E. Telmateia. Ehrh. (Great Water Horsetail.) 

 Wet damp ground. 4, 5. 



Bentley Priory, Harrow Weald. 



2. E. arvense. L. (Corn Horsetail.) 

 Corn-fields and road sides. 4, 5. 

 Abundant. 



3. E. limosum. L. (Smooth Naked Horsetail.) 

 Sides of rivers. 6, 7. 



Ruislip Reservoir, and ditches on Ruislip Common. 

 Stanmore Heath. (Flor. Midd.) 



4. E. palustre. L. (Marsh Horsetail.) 

 Boggy soils. 6, 7. 



Side of the Canal, near Greenford. 



5. E. sylvaticum. L. (Branched Wood Horsetail.) 

 Moist woods, and hedge banks. 4, 5. 



Abundant on Harrow Weald Common. An unfrequent 

 and peculiarly graceful species. 



