30
was not recorded in l891, and is not mentioned as occurring
in the canal in Jermyn's Flora of Essex. Also noticeable
was the virtual absence of emergent vegetation in the main
channel, except on shallow shelving bends - such plants as
the water lilies and pondweeds being chewed-off to screw
depth, a pitiful sight now shared by all canals with
motorised screw-driven craft. Furthermore the once numerous
marshy fields and sedge-beds along the canal have now all been
drained and arable or intensively grazed grass fields now
come right up to the canal banks. These changes probably
account for the absence today of Sonchus palustris (Marsh
Thistle), Thalictrum flavum (Meadow Rue) and Lysimachia
vulgaris (Yellow Loosestrife), all recorded in 1891. Other
species not seen that may well have gone since 1891 for the
same reasons are Caltha palustris (Marsh Marigold) and
Valeriana officinalis (Valerian).
The apparent absence of Potamogeton natans and the failure
to refind P. praelongus, seen in the canal by Stan Jermyn
in 1964, suggests that there have also been changes in the
aquatic flora. One obvious change is the addition to the
aquatic flora of Elodea nuttallii, a recently introduced
species that seems to be spreading extremely rapidly and
is apparently ousting that more familiar introduced Elodea,
the Canadian Pondweed, Elodea canadensis, apparently absent
from the canal today. The marginal vegetation is now con-
fined to a narrow belt at the edges of the canal but most
species recorded in 1891 seem to be holding their own today.
One possible increase is that of the Sweet Flag, an intro-
duced species only recorded at Springfield in l891, but now
scattered all along the canal (Acorus calamus).
On arrival at Beeleigh the party disembarked for half an
hour to stretch the legs and build up an appetite for the
tea and gateaux served on the return trip. A large colony
of Lesser Calamint (Calamintha nepeta) was located by the
road to the north of the canal, and the fern Asplenium
adiantum-nigrum (Black Spleenwort) was found on a nearby
bridge. A remarkable discovery was the abundance of the
Lesser Reedmace (Typha angustifolia), all along the
navigation, with what must surely be the largest colony in
Essex near Beeleigh Lock. This species is commonly