84 ferns. [Equisetum. 
Fig. — E. B. 2021. — Bolt. 35. — Flo. Dan. 1183. — Lob. Icon. 795. — Ger. Her. 
1114. — Schk. 168, 169. 
Des. — Stem upright, branched throughout, 6 to 12 inches high, 
dark green, deeply channeled with G or 8 grooves. Branches five- 
sided, simple, ascending, six to ten in a whorl, a less number of 
and shorter branches upwards. Catkins terminal, cylindrical, 
tapering, on a long stalk, erect ; found in May and June, sometimes 
before the branches, at other times appearing long after the stem 
becomes branched. Sheaths large, loose, with a few long tapering 
black teetb. 
/3 ( alpinum ), smaller, upper branches abortive, 
y ( polystachion ), upper branches elongated and fruitful. 
The second variety is always found in such situations as convince us that its 
peculiar conformation arises from its being nipped by frost or cropped by cattle, 
especially as when thus proliferous, the main stem is almost always injured at the 
top ; a proof that here, as often is the case with Flowering Plants, the early 
shoots being by any cause destroyed, the plant makes an effort to repair the 
loss at a later season of the year by producing others. 
Sit. and IIab. — V ery common in ponds, wet valleys, water-courses, &c. 
— /3 : Breadalbane Mountain, Perthshire, at 3000 feet high, Mr. II. C. Watson. 
— y : No certain habitat of this can be given, because it is an accidental state of 
the plant, and not a permanent variety. I have often found it in Richmond Park, 
Surrey, and by the side of the Lea River at Stratford, Essex. 
Geo. — Common throughout Europe, and in North America. 
/.—EQUISETUM VARIEGATUM. 
VARIEGATED ROUGH HORSE-TAIL. 
(Plate IX, fig. 7.) 
Cha. — Stem procumbent, rough, 1 with 4 — 10 grooves. Sheaths 
black at top. Teeth few, white, and persistent. 
Svn. — Equisetum variegatum, Willd., Schk., Smith, Hook., Mack. — Equise- 
tum arenarium, of authors . — Equisetum tenue, Hopp. 
Fig. — E. B. 1987. 
Des. — Rootstock very woolly. Stem branched at the base only, 
rather procumbent in habit, 4 to 12 inches high, of a green colour, 
rough and channeled. Catkins terminal, ovate, at first black and 
sessile, afterwards long-stalked, yellow and brown. Sheaths of the 
stem widening at top, green below, black only at their"tipper part, 
which is sharply, but not numerously toothed, the upper sheath of 
the stem being much larger and more spreading than the rest. 
Its smaller size, recumbent habit, differently-coloured sheaths, with their 
prominent and permanent teetb, serve to distinguish this from E. hycmale. 
Sit. — O n the sandy sea-shore in the north of the kingdom. 
