Equisetum hyemale. 
Plants 1 m. more or less in height; stems 5 mm. or 
wider at the base; sheaths about 1 cm long, somewhat 
spreading, marked with one or two narrow girdles ; teeth 
acuminate, caducous; spikes somewhat conical, mucron- 
ate. 
Along riverbanks and creeks. 
tt Stems of two kinds. 
* Branches simple. 
3. E. arvense L. Reler: 
Etquisetum arvense &c. Gron. F\, Virg. 123. 
£. arvense £. Sp. Pl. 1061. Heaton, |. c. 676. 
Underw. in Ill. Fl. 1:36; Nat. Ferns 127; in 
Britt. Man. 22. Clute, 1. c. 43. 
HORSETAIL. 
Plants 3-6 dm. or higher; sterile stems bearing num- 
erous linear branches of variable lengths; sheaths about 
1 cm, long including the darkbrown, acuminate teeth; 
fertile stems (appearing in early spring) about 2 dm. in 
heigth, branchless; spikes oblong, 3 cm. or shorter. 
Along railroad embankments, in fields 
and low ground. 
** Branches compound. 
E. sylvaticum L. ‘alle ries 
E-quisetum sylvaticum L.\.c. Eaton, \. ce. Und. 
in Ill. Fl. 1: 36; Nat. Ferns 127; in Britt, Man. 
22. Clute, lec. 55. 
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