S6 
EQUTSETACE^.. 
receive the smallest, most recumbent, and most extreme speci- 
mens, is selected as the field of observation. The roots of 
the Barry plant scarcely differ from those of the Deeside vari- 
ety. The stems are of the same variable length and number of 
articulations, with 4 — 10 striae : they are completely prostrate, 
except in a few instances, when supported by Ammopliila are- 
naria. When not sheltered by that or any other plant, they are 
brownish on the upper or exposed side and green on the under ; 
it is, however, possible that the brown colour may be the effect 
of the lateness of the season. On the upper side also the bands 
of black upon the sheaths run farther down the stem than they 
do on the under side. The teeth are wedge-shaped, not ovate 
as at Banchory : the bristles are longer, and apparently more 
persistent. The catkins are in general more exserted and ma- 
tured, and, as well as the stems, have sometimes a reddish tinge. 
The plant seems to branch in the same manner as in the higher 
and moist situation on Deeside, 150 feet above the sea. When 
the sand is compacted by small plants which afford no shelter to 
the Equisetum, the latter is generally very small, slender and 
filiform ; where the sand is loose or the plant has shelter, its 
growth is much stronger, and in the sheltered situation it is 
greener. In no case does the plant attain the same size as on 
Deeside. Some specimens slightly resemble E. Mackaii, but 
are perfectly distinct ; the resemblance arises from the bristles 
being longer, and the amount of black upon the sheaths greater 
than in the usual state of the plant.”^' It will be seen that these 
opposite opinions concerning the two more usual forms of the 
plant, proceeding as they do from botanists of acknowledged 
judgment, nearly counteract each other, and the question as to 
their distinctness or identity, still remains sub judice. 
The roots and rhizoma, like those of E. Mackaii, present no 
characters by which I can distinguish this species from E. hy~ 
emale. Like the roots of many other plants when growing in 
loose sand, those of the present species are frequently clothed 
with a quantity of matted fibrill 80 : the stems are short, often 
semiprostrate, and the internodes are short and frequently some- 
* Phylologist, 447. 
