Isoetes saccharata, 
Plants growing in colonies; leaves linear, olive-green _ 
in color, 5~13. cm. long, 10--20in a cluster; sporangia 
oblong, 5 mm. or less in length. 
Along riverbanks bet ween tidal limits. 
In various localities along Chesapeake Bay from Wi- 
comico River northward: along Potomac River, Eastern 
Branch, Fourmile Run, Steede; Hunting Creek, Vasey, 
_ Coville; Notley Hall, Mt. Vernon, Coville. 
The geographical distribution of this species and its 
forms has been discussed atlength by G. H. Shul/[Bot. — 
Gaz, 36: 187. 1903. |. 
tft Leaves 20 cm. or longer. 
2.1. valida (Engelm.) Clute. 
Lsoetes Eingelmanni valida Engelm. in Gray, Man. 
677; ed./6. 700. Underw. in Il P11: 48 Nat. 
Ferns 147; in Britt. Man. 29. 
I. valida Clute, Fern Allies 236. 
Plants sometimes 4 cm. thick at the base; leaves 50 to 
200 in number, sometimes 6 dm. long; sporangia ob- 
long, 1-2 cm. long. 
In pools and ditches. Summer, 
Near Great Falls, Potomac River, Ward; Salt Pond 
Mt., Va., Candy. 
26. EQUISETUM Plinius. 
Liquisetum, hippurits Grecis dicta etin pratts vt- 
tuperata nobis —est autem pilusterre equine saete 
similis. Plinius, Hist. Nat. xxvi, 132. 
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