58 THE ESSEX NATURALIST
in the purplish-coloured stems. The flowers are white. Both these plants occur-
red on a rubbish-tip at Pitsea. On a small rubbish-tip at Bast Hanningfield
an unusual Melilot appeared in October, 1956. Melilotus messanensis (L.) All.,
(M. sicula (Turra) Jackson) is a south European species and its occurrence
here is probably due to the importation of grain for cattle or chicken feeding.
At the same place there were also found several plants of Guizotia abyssinica
(L.f.) Cass which is not infrequently found on such sites. This is an E.
African species which is cultivated in that place, in the W. Indies and in
India for the oil to be obtained from its seeds. There were also several
plants of the Darnel, Lolium temulentum L. At Woodham Mortimer a plant
growing on the roadside has long occupied attention but it has now been
identified as Lactuca bourgeai (Boiss.) Irish & Taylor. Doubtless this is an
escape or an introduction but its persistence over a number of years calls for
notice.
The practice of keeping aquaria of tropical fish which was fashionable and
attained its greatest popularity a few years ago is probably responsible for the
introduction to some Essex waters of a South African species Lagarosiphon
major (Ridley) C. E. Moss. This species which was also termed 'Elodea crispa'
by the dealers, is used for aerating the water in aquaria. Surplus or dis-
carded pieces thrown out by aquarists have become so well established in the
Hollow Ponds at Whipps Cross, Leytonstone, that portions of the ponds have
become congested with it. It has been there for several years. The same
species was found by Mr. Jermyn in the Blackwater-Chelmer canal on 16th
July, 1950. A further search will probably reveal its presence in other places
in the county.
Further north the enthusiasm of some local schools participating in the
Distribution Maps Scheme of the Botanical Society of the British Isles has
revealed the presence in 1956 of the Early Spring Vetch, Vicia lathyroides
L., in the parish of Langham, near Colchester. In the Hempstead area Stachys
ambigua Sm., the hybrid between S. palustris L., and S. sylvatica L., was
reported this year by Mr. D. Allen and Mrs. J. Russell.
The rubbish tips on the borders of suburban London have produced various
plants. In 1953 the Barking rubbish tip proved fruitful. Mr. S. T. Jermyn
and I discovered the Dodder Cuscuta australis R.Br., subsp. cesatiana (Bertolini)
Riori and Paoletti. Other plants noted there included Abutilon theophrasti Med.,
Centaurea diluta Ait., Datura ferox L., Ambrosia artemisaefolia L., Galinsoga
ciliata (Raf.) Blake, Heliotropium europaeum L., Lappula myosotis Moench,
Lolium temulentum L., Medicago murex Willd., Nicandra physalodes (L.)
Gaertn., Rapistrum perenne (L.) All., Solanum sarrachoides Sendtn., S.
triflorum Nuttal, Tagetes minuta L., Trigonella humosa L., T. foenum-graecum
L., and Xanthium spinosum L. In addition the alien Mugwort Artemisia
verlotorum Lam., was found well distributed over most of the tip.
From seed collected on the tip during 1953 Dr. D. P. Young grew several
vetches including Vicia monantha Retz ssp. triflora (Ten.) Burtt and Lewis.
In autumn, 1953, at one area on Thames-side near Rainham, the Spiny
Saltwort, Salsola pestifera A. Nelson occurred in such abundance as to make it