214 NOTES ON ALIEN AND CASUAL PLANTS.
the casuals, White or Evening Campion (Lychnis alba), Bladder
Campion (Silene Cucubalus), and the apricot-scented Night-flower-
ing Catch-fly (S. noctiflora). On another estate, from which the
turf had been removed, leaving the clay exposed, the most
noteworthy plant found was the alien, Melilotus indica, a native
of warm countries. The colonist, Lesser Wart-cress (Coronopus
didymus) and its commoner relative, Greater Wart-cress (C. ruellii),
were also observed, as well as Many-seeded Goosefoot (Chow-
podium polyspermum), which turns up in some plenty hereabout
on newly-disturbed wastes.
I have once met with the colonists, Corn Crowfoot (Ranunculus
arvensis) and Penny Cress (Thlaspi arvense) in a cornfield at
Hale End, and on the railway bank the denizen, Sand rocket
(Diplotaxis muralis v. babingtonii), the casuals, Mountain Crane's
bill (Geranium pyrenaicum) and Wild Carrot (Daucus carota)
and also Galium erectum and the Acrid Lettuce (Lactuca virosa),
which I think must be considered casuals as they occur nowhere
else in the district, so far as I know. All except the last are well
established.
In my garden the alien, Alkanna lutea, a yellow flowered South
European Boragewort. and the casual, Hare's Ear (Bupleurum
rotundifolium) have occurred, which I cannot at all account for,
but the latter has turned up at Chingford for several years
in at least one spot. Henbit Deadnettle (Lamium amplexicaule)
has also been recorded from Hale End, where it appears to be a
casual, as it is of rare occurrence, and the colonist, Green Millet
(Setaria viridis) has appeared at Walthamstow.
Passing on now to the Woodford Green district, mention
may be made first of Impatiens parviflora, a small-flowered balsam
native in mountain woods in Siberia, a specimen of which was
found in 1906. In 1907 the species was better represented,
there being about a dozen plants, and it is still spreading. On the
Monkhams estate, recently cut up and partly built on, the casual.
Stinking Groundsel (Senecio viscosus), the aliens, Galinsoga
parviflora and White Melilot (M. alba), with the casuals, Common
Flax (Linum usitatissimum), Field Woodruff (Asperula arvensis)
and Sisymbrium pannonicum, turned up on the newly-made
roadways, whilst on the adjoining field, from which the turf
had been removed partly, several plants of the colonist, Purple
Cow Wheat (Melampyrum arvense) showed up conspicuously