54 
^BRITISH WILD FLOWERS. 
exceeding one foot. The flowers and seed-pods are, however, as much smaller than those of the white Mustard 
as the stem and leaves are larger. The seed-pods also are pressed close to the stem, instead of spreading. The 
plant is an annual, and flowers in June. 
GENUS XXVII. 
THE SAND ROCKET. (Diplotaxis, Dec.) 
Lin. Syst. TETRADYNAMIA SILIQUOSA. 
Generic Character.— Siliqua compressed, linear. Seeds in two rows, ovate. Calyx equal at the base. Flowers yellow or white. Calyxes 
usually covered with soft down. {Dec.) 
Description, &c. —There are only two species in this genus, and both were formerly included in Sinapis, 
but have been separated on account of the seeds forming two rows in the seed-pod, instead of one. The two 
species are: the common Sand Rocket, D. muralis , a very small annual weed, which is very abundant in sandy 
ground near the sea, particularly in the Isle of Thanet ; and the Wall Rocket, D. tenuifolia, which is a hand¬ 
some plant with pale yellow flowers, nearly as large as those of the Wall-flower, and glaucous, pinnatifid leaves 
which are rather fleshy. The whole plant has a very strong smell, which is said to bear some resemblance to 
that of a Wall-flower at a distance; but to be very disagreeable when close. It is a perennial, and flowers 
from July to September. The Wall Rocket is very common on old walls in the southern counties of England, 
and it is said to have been particularly abundant on old London bridge. 
X.—THE CRESS-ROCKET TRIBE. 
Silicle with concave valves opening lengthwise; partition elliptical. Seeds globose. 
GENUS XXVIII. 
THE CRESS-ROCKET. (Vella, Lin.) 
Lin. Syst. TETRADYNAMIA SILICULOSA. 
Generic Character. —Stamens all distinct. Style ovate, flat, foliaceous. Flowers small, pale-yellow. Silicuke pendulous, with inflexed 
stalks. {Dec.) 
Description, &c. —There are only two or three species in this genus; and of these, only one is a native of 
England. The genus is characterised by the style being dilated or winged, so as to bear some resemblance to 
the beak of a duck, and this curious style remains on the seed-pod till the seed is ripe. Veler is the Celtic name 
for the Cress. 
1.—THE ANNUAL CRESS-ROCKET. (Vella annua, Lin.) 
Synonyme. —Carrichtera annua, Dec. I Specific Character. — Leaves lipinnatifid. Fruit pendulous. 
Engravings. —Eng. Bot., t. 1442 ; 2nd ed., t. 896. | {Smith.) 
Description, &c. —This is a very curious little plant ; but is a doubtful native, having only been found on 
Salisbury Plain. The flowers are sometimes white, and sometimes yellow ; but the petals are always curiously 
veined with dark purple. The seed-pods are erect at first, but hang down as the seeds ripen. It flowers in 
J une. 
