1 80 Equisetaceae. 



EQUISE'TUM MAXIMUM (77). Great Water Horsetail. 4—5. 



(181 1) Barren stem 3 — 4 ft. with about 30 strise and nearly erect simple 

 branches, fruiting stem 8—10 in. with large lax sheaths. Bogs and 

 ditches, 



EQUISE'TUM ARVEN'SE (108). Corn Horsetail. 4. Barren stems 



(181 2) with 8—16 grooves rough ending in a long naked point, branches 

 crowded spreading, fertile stems stout short with distant loose sheaths. 

 Roadsides and fields. 



EQUISE'TUM SYLVAT'ICUM (90). Branched Wood Horsetail. 



(1814) 4—5. Stem with about 12 grooves, sheaths lax with 3—4 long mem- 

 branous teeth, branches compound whorled recurved or deflexed. 

 Moist woods and banks. 



EQUISE'TUM LIMO'SUM (103). Smooth Naked Horsetail. 6—7. 

 (1817) Stem I — 3 ft. smooth with faint stria;, branches wanting or simple erect 

 whorled, sheaths short with short rigid teeth. Bogs. 



Equise'tura hyema'le (41). Rough Horsetail. 7 — 8. Stem rough with 

 (1818)8—12 striae, branches radical long flexuous, sheaths close whitish 

 with black base and tip, teeth black bristle-pointed deciduous 



[G. {Settle), S. 



Equise'tum variega'tum (24). Variegated Rough Horsetail. 7—8. Stems 



(1821) rough with 4 — 10 furrows filiform simple or branched only at the base, 



sheaths short green below black above .with obtuse bristle-pointed teeth. 



[G. {Swarth moor). 



EQUISE'TUM PALUS'TRE(i04). Marsh Horsetail. 6—7. Stems 

 (1815)6—18 in. with simple whorled branches with 5 — 12 deep grooves, 

 sheaths short, teeth acute with membranous tips. Bogs. 



