Isoetes ISOETAC— EQUISETAC. Equisetwn 



Plain, except near the Fall Line: ponds, Townsend (NC), Canby, 

 4 July 1896 (D); streamlet in swampy woods, just w. of Townsend 

 (NC), Long, 3 July 1909 (A); ditches, Ellendale (S), Canhy, 24 

 July 1893 (D); edge of Custis pond in woods. Savage Neck (No), 

 Fernald, Long & Fogg, 5228, in 1935. 



Var. valida Engelm, 



Specimens from four collections from New Castle County, 

 three of them dating from the last century, were determined by 

 T. C. Palmer. Pondhole in field just w. of Vandyke Station 

 (NC), Long, 3 July 1909 (A). 



I. riparia Engelm. 



Collected in tidal mud of Delaware River, at and north of 

 Wilmington, by Canhy, Commons, and E. Tatnall, between 1862 

 and 1896; not seen since then. 



Wastes from oil refineries have nearly exterminated the littoral 

 flora of this region. 



I. saccharata Engelm. 



Common in tidal mud of Elk, Bohemia, Chester, Choptank, 

 Nanticoke and Wicomico Rivers and their tributaries, in brackish 

 to fresh water; also in a fresh- water pond at Milford (S), Long, 21 

 July 1908 (A). 



EQUISETACEAE (Horsetail Family) 



Equisetum L. Horsetail. 



E. arvense L. Common Field Horsetail. 



Common and abundant in the Piedmont area; less frequent 

 southward on the Coastal Plain, to the Virginia line. In thickets 

 and ditches and on roadsides and railroad banks, apparently pre- 

 ferring sterile soil. Spores ripe in April. 



E. sylvaticum L. var. multiramosum (Fern.) Wherry. Wood 

 Horsetail. 

 Rare, if still present, in our area: Adams Mill, near Rockland 

 (NC), Commons, May 1864 (A); damp roadside west of Hockessin 

 (NC), Canby, 8 May 1897 (D). 



E. fluviatile L. {E. limosum L.) Water Horsetail. 



Infrequent to rare, on river shores and along streamlets: Bellevue 

 (NC), near station, Commons, June 1868 (A); Port Penn (NC), J. 



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