62 
FERNS. 
[Equisetum. 
EQUISETUM, Linn. HORSE-TAIL. 
PLATE OF GENERA, FIG. XX. 
A widely-distributed but not very extensive yenus, which inhabits for the most 
part temperate and cold countries. The species now liviny are all small plants, 
but the fossil remains of the Equisetacece show that at some former period 
yigantic specimens must have been f requent. Our plants prefer watery situa- 
tions and strony soil. They may be divided into sections as follmvs . — 
* Fertile stems naked, succeeded by branched barren ones. 
** Fertile stems branched from their first growth. 
*** Fertile stems not branched at first, but finally becoming so. 
**** Fertile stems always remaining simple, barren stems the same. 
Equis. fluviatile, drummondii, and arvense , belony to the first section ; E. syl- 
vaticum to the second j E. palustre to thethird; E. varieyatum and hyemale to 
the fourth. , . 
1.— EQUISETUM FLUVIATILE. 
GREAT HORSE-TAIL. WATER HORSE-TAIL. 
(Plate 5, fig. 7.) 
Cha. — D arren stems erect, with 30 to 40 branches in each whorl. 
Fertile stems with 7 or 8 toothed loose sheaths. 
Syn. — Equisetum fluviatile, Linn., WiUd. , Smith, Hook., Bolt., Huds., 
Liyhtf., With., Gray . — Equisetum telmateia, Ehrh., Flo. Dan. — Equis. 
eburneum, Roth, Schr. — Equis. majus, Ray, Ger. — E. maximum, Lam. 
Fig .—E. B. 2022 .—Bolt. 36, 37 .—Ger. Her. 1113.— Flo. Dan. 1469. 
Des. — Barren stem 2 to 4 feet high, quite erect, white, succulent, 
surrounded by w horls of from 30 to 40 branches. Branches rapidly 
growing upon the stem as soon as it issues from the ground, giving 
it soon a broad-topped appearance. In its future growth this blunt 
character is lost, the main stem becoming elongated, and the 
branches are then long, slender, simple, jointed, ascending, with 4 
or 5 large channels along their surface, and at the angles of these 4 
or 5 other very minute ones. Fertile stems 4 to 6 inches high, 
arising in March or April, and decaying as the barren stems arise, 
reddish white, extremely succulent, and wholly without branches at 
any time. Their sheaths 4 to 6 in number, nearly an inch long, and 
generally so close together as to overlap each other, very deeply, 
sharply, and numerously toothed. Catkin large, conical, blackish. 
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 arc usually placed, into a drier spot of ground. Mr. 
W. Wilson attributes this state of the plant to drought as here stated, and adds 
that lie has seen a specimen gathered near Bangor where this catkin was topped 
by a prolongation of the branched frond, (July 1836.) 
