PLANTS OF TUNBRIDGE WELLS. 347 
by the mill at Riverhead. The miller first noticed it last 
spring, and it has since increased to such an extent that 
the mill-dam is at present quite choked with its matted 
stems. All the efforts of laborious raking have proved 
insufficient to keep it down. In this station, as in many 
others, the water-pest may have been planted for an expe- 
riment; but it is hoped that no one who reflects upon the 
mischief and damage caused by such a weed will aid to 
extend an evil for which as yet we do not know any effec- 
tual remedy. 
Juniperus communis. The abundance of fine examples of this 
elegant shrub upon the common at Southborough plainly 
shows it is not on chalk only that it flourishes. 
A, Atriplex deltoidea, Bab. This, which is treated as the type 
of A. hastata by Grenier and Godron, was sufficiently 
abundant by the roadsides at the outskirts of Tunbridge 
Wells. 
A. Atriplex erecta, Huds., was fully as common, if not more so, 
than A. angustifolia. 
Lastrea spinulosa, Presl. There is a peculiarity in this Fern which 
I have not seen noticed, From the examination of a consi- 
derable number of roots, it has appeared to me that a barren 
frond is very commonly evolved from the same crown, and 
alongside of the ordinary fertile one. This barren frond 
has quite a different form, and approaches L. wliginosa in 
its decurrent pinunules, while the breadth of outline reminds 
one of L. dilatata. It is usually thrown up in autumn, 
and occasionally bears a few sori, so that there is not that 
clear line of distinction here between the two kinds as there is 
in its allies L. uliginosa and L. cristata. To myself it ap- 
pears that this occurrence of a sterile frond upon L. spinu- 
losa bears in a most interesting manner upon the specific 
identity of all three Ferns as advocated by Mr. Moore of 
Chelsea. 
As regards the sori of the fertile frond too, they are by 
no means always absent from the lower pinne, and in luxu- 
riant specimens depart considerably from the two-ranked 
order which has been employed as a character to distinguish 
the species. The scales also varied so far as this, that in 
the yellowish form which grows in the open bog, and 
