THE PRESENT FLORA OF WEST HAM WASTES. 173
many Black Headed Gulls, with tame Pigeons, picking up scraps
among the stones exposed at ebbtide ; also a pair of Grey Wag-
tails, the gusts of wind ruffling their yellow under feathers : the
air was fresh with a salty tang from the Thames a mile and a
half away. We could sympathize with John Camden's descrip-
tion, written in 1586:—"When Maud wife to Henry the First
"had very narrowly escaped drowning, she took care to have
"a bridge built somewhat lower down the river [than Old Ford]
"at Stratford, where being divided into three streams, it washes
"the green meadows and makes them look very charming."4
Here follows the list of the plants we found, with notes on
some that are of special interest. The names are in the order
given in Hayward's Botanists' Pocket-Book, ed. xiii. A.
denotes plants found south of the High Street; B. those found
north of High Street ; F. in flower.
Ranunculus repens L., Creeping Buttercup. A, B. Several
colonies.
R. sceleratus L., Celery-leaved Buttercup. A. A few
plants. F. This and the next were no doubt from seed brought
in clearing the channels.
Radicula palustris Moench., Marsh Water-cress. A. Abun-
dant. F.
Sinapis arvensis L. Charlock. A, B. A few plants. F.
Sisymbrium officinale Scop. Hedge Mustard. B, F.
S. altissimum L. (syn. S. pannonicum Jacq., S. sinapistrum
Crantz). A, B. Very abundant both in flower and fruit. The
dead plants with their stiff divergent branches form bushes
a yard across ; the long slender pods each contain about sixty
seeds, and a large bush must bear about 100,000 seeds. It is
one of the "Tumble-weeds," so-called from their shallow roots
being easily dislodged, the plant then, wind-borne, tumbling
over and over along the surface of the ground, scattering seed
as it rolls. "Tumble-weeds" are characteristic of open prairie
or desert flora. S. altissimum is a comparatively recent addition
to the British Flora. It is apparently native to the South of
Europe and is becoming rapidly and widely distributed through
human agency. In Macoun's Catalogue of Canadian Plants
(1890) it is described as "introduced in a number of places
4 See Camden's Britannica, 1st edition in Latin, 1586; 2nd edition translated into English
by Edmund Gibson, Bishop of Lincoln, 1753, p. 406.