108 



METROPOLITAN PARK FLORA. 



that the Blue Hills and Middlesex Fells Reservations have 

 been more thoroughly worked over than the Stony Brook and 

 Beaver Brook Reservations, although the latter can scarcely be 

 any the less interesting to a botanist studying the Ferns and 

 their Allies. 



The arrangement adopted here is that of the late Prof. D. C. 

 Eaton, in the 6th edition of Gray's Manual, and comments are 

 made in connection with the different species for the purpose 

 of calling attention to certain points that may lead to a more 

 thorough investigation, and result in restoring under proper 

 guidance many species once common, or fairly plentiful, but 

 now nearly or wholly extirpated from various causes now 

 happily within control and future prevention. 



EQUISETACE/4E. Horsetail Family. 



EQUISETUM, L. Horsetail. Scouring Rush. 

 E. arvense, L. Common Horsetail. 



Common everywhere in sandy soil ; the fertile stems appear- 

 ing very early in spring and soon perishing, the sterile stems 

 appearing later and lasting all summer. B and M, common : — 

 BB*, near the ponds. 



E. sylvaticum, L. 



A rather scarce plant growing in wet shady woodlands ; the 

 fertile stems fruiting early in spring, the fruit soon withering 

 away, but the stems remaining all summer with the sterile. 

 B*, occurs. 

 E. limosura, L. 



A rare plant; stems all of one kind, in shallow water, fruit- 

 ing in summer. M *, occasional ; ditch, S. of Bear Hill ; 

 meadows, N. side of Spot Pond, etc.: — S*, meadow near 

 Office. 



E. hyemale, L. Scouring Rush. 



Wet places, evergreen. M*, occurs: — B B, meadow near 

 the brook. 



