APPENDIX B. 
411 
(B, p. 29). 
Description of Equisetum hyemalej Mackaii and variegatum, as found 
on the baftks and in the bed of the River Dee. By J. B. Brichan. 
(From ‘ The Phytologist/ p. 369). 
Equisetum hyemale. 
Root creeping, jointed, branched. Stems several from one branch of the 
root, or branched at the base, one to three feet high, or upwards, stout, erect or 
decumbent, articulated and fluted, occasionally throwing out catkins or very 
small branches near the top. Ridges or furrows fourteen to twenty-one in num- 
ber, in luxuriant specimens twenty-eight ; ridges grooved, and, as well as the 
furrows, grained like a file. Sheaths widest at top, at first pale green, with a 
black crenate rim ; afterwards entirely black ; ultimately white, with a broad 
black band at the base, the rim remaining black as before. The uppermost 
sheaths of the root generally., and the upper and lower of the younger stems oc- 
casionally., bear black, membranous, flexuose, deciduous teeth or bristles. The 
sheath of the catkin is invariably and persistently toothed. Catkins terminal, 
more rarely lateral, and in that case either single or in opposite pairs. 
Equisetum Mackaii. 
Root creeping, jointed, branched. Stems several from one branch of the 
root, or branched at the base, slender, often filiform, erect or decumbent, one to 
two and a half feet high, consisting of articulations from one to two and a half 
inches in length. The older stems frequently throw out long slender branches, 
which generally bear catkins. The stems are fluted, the ridges grooved, and 
both ridges and furrows grained, as in E. hyemale. Number of ridges or fur- 
rows eight to twelve. Sheaths cylindrical, at first pale or yellowish green, with 
a narrow black band immediately under the teeth ; ultimately wholly black, with 
the lower border of the black entire. Teeth equal in number to the ridges, mem- 
branaceous, white at the edge, long and tapering, terminating in a flexuose bris- 
tle which is generally black but sometimes white, in which case the white mar- 
gin of the teeth is broader: they often adhere in pairs, and are decidedly per- 
sistent. Catkins terminal, either on the stems or on the branches. 
Equisetum variegatum. 
Root creeping, jointed, branched. Stems many, three to twenty inches long, 
branched at the base and upwards, generally but not invariably decumbent and 
filiform, rather brittle, consisting of numerous fluted articulations, half an inch 
to an inch and a half long. Ridges or furrows five to nine, the former grooved, 
and both grained as in E. hyemale and E. Mackaii. Sheaths slightly swollen 
upwards, the upper half black. Lower border of the black waved or toothed, the 
