80 
FERNS. 
[Equisetum . 
1. — EQUISETUM FLUVIATILE. 
GREAT HORSE-TAIL. WATER HORSE-TAIL. 
(Plate IX, fig. 1.) 
Cha. — B arren steins erect, with thirty to forty branches in each 
whorl. Fertile stems short with loose sheaths, having numerous 
2-ribbed teeth. 
Syx. — Equisetum fluviatile, Linn., Willd., Smith, ITook., Bolt., Huds., Light/., 
With., Gray. — E. telmateia, Bah., Ehrh., Flo. Dan. — E. eburneum, Roth., 
Schr. — E. majus, Ray, Ger. — E. maximum, Law. 
Fig. — E. B. 2022.— Bolt. 36, 37 .—Ger. Her. 1113.— Flo. Dan. 1469. 
Des. — Barren stem 2 to 4 feet high, with about 30 grooves, 
quite erect, whitish, succulent, surrounded by whorls of from thirty 
to forty branches. Branches rapidly growing upon the stem as 
soon as it issues from the ground, giving it soon a broad-topped 
appearance. In its subsequent growth this blunt character is lost, 
the main stem becoming elongated, and the branches are then long, 
slender, simple, jointed, ascending, with channels along their sur- 
face, and at the angles of these other very minute ones. Fertile 
stems 4 to 6 inches high, atising in March or April, and decaying 
as the barren stems arise, reddish-white, extremely succulent, and 
wholly without branches at any time. Their sheaths, four to six in 
number, are nearly an inch long, and generally so close together as 
to overlap each other, very deeply, sharply, and numerously toothed. 
Catkin large and conical. 
Withering says, “fertile stems sometimes leafy.” He ought rather to have 
said, barren stems sometimes fruitful; as a catkin is often found in the middle or 
latter part of summer terminating it, particularly if the weather has been dry for 
some time previously ; in fact it may be produced at any time with such cultivated 
plants as grow in pots, merely by removing the pots from the watery situation in 
which they are usually placed into a drier spot of ground. Mr. W. Wilson attri- 
butes this state of the plant to drought, as here stated, and adds that he has seen 
a specimen gathered near Bangor where this catkin was topped by a prolongation 
of the branched frond (July 1836). 
The name fluviatile is not so applicable to this species as it would have been to 
some ot hers ; it is rarely found on the banks of rivers or ponds, nor do I remember 
ever having seen it growing in the water. It rather affects strong, loamy, damp 
ground, clayey banks, and swampy bogs. 
IIah. — Very abundant in some parts of England, as about London, in Hants, 
Bucks, &c. ; but Mr. Watson thinks scarcely a common plant generally. 
Geo. — Europe, Siberia, North America. 
