Pl.end.cr. 4. EQUISET. 22. Equisetum. 25 



Fam. IV. 4. EQUISETACE^. Richard. Pellaicp, 

 Hoffman ; FUicum pars, Linnaeus, Jus- 

 sieu ; Peltigerfe, Batsch ; GonostendeSy 

 Wilklenov/. 



Fructification terminal, in the peltate scales of an ament ; 

 involucra bivalve ; seeds P numerous, naked, with four very 

 hygrometrical threads twisting and untwisting round them. 

 — Plant leafless ; branches verticillate, furrowed, jointed ; 

 joints girt with a one-leaf sheath. 



22. EQUISETUM. Plinii H. N. 26, 13. Horsetail 



Character, same as that of the order; there being no 

 other genus. — Herb strongly astringent. 



1. Equisetum hyemale. Winter horsetail. 

 Stem naked, erect, very rough, base rather branchy; 



spike terminal; sheaths white, with a black base and tip; 

 teeth bearded, all falling off. 



Equisetum nudum, Rail Syn, 131, 11 ; Ger. em. 1113. 



E.junceum seu nudum, Park. 1201. 



Equisetum hyemale, Lin. S. P. 1517. 



Naked horsetail. Hough horsetail. Shavegrass, Dutch rushes. 



In marshes and moist woods; perennial; July and August. 



Stem half a yard high, sea-green, very rough ; sheaths 

 short ; amentum ovate, black. 



Used for polishing wood and brass; the epidermis 

 abounding in silica. 



0. paucifolium. Leaves few. 



y. ramosum. Lateral branches numerous. 



2. Equisetum variegatum. Variegated horsetail. 

 Stem naked, branchy at the base, stiff, smoothish; spike 



terminal ; sheaths black, white at the tip ; teeth white, dia- 

 phanous, cuspidate. 



E. nudum minus variegatum Basiliense, Rail Syn. 130, 3- 



E. tenue, Hoppe. 



Equisetum variegatum, Willd. S, P. 



Banks of rivers; perennial; July. 



Stem 6 inches high, quite simple, erect, round, slender, 

 stiff, streaked, smoothish. 

 6 



