CRUCIFERAE. 163 
nerves, not opening suddenly with a spring. Style very short or 
absent. Stigma entire or slightly 2-lobed. Replum transparent. 
Seeds compressed, usually winged at the top. 
Annual or perennial herbs, glabrous or clothed with simple, 
forked, or starlike hairs. Radical leaves often spatulate. Stem 
leaves sessile, all entire, toothed or pinnatifid. Flowers white, 
yellowish, rose-colour, or more rarely purple, disposed in corymbs 
or short racemes which afterwards elongate. 
Wall Cress. 
French, Arabette. German, Gansekraut. 
The first plants described as belonging to this genus were brought from Arabia; 
hence their name. 
SPECIES I—ARABIS THALIANA. Linn. 
Puate CXV.* 
Conringia Thaliana, Reich. Ic. Fl. Germ. et Helv. Vol. II. Zetr. Tab. LX. Fig. 4380. 
Sisymbrium Thalianum, Gaud. Lab. Man. Brit. Bot. ed. v. p. 26. Hook. & Arn. Brit, 
F). ed. viii. p. 35. 
Rootstock none. Radical leaves oblong, attenuated at the 
base, and stalked. Stem leaves sessile, elliptical or strap-shaped, 
attenuated towards the base, not amplexicaul ; all entire or dentate. 
Petals oblanceolate, twice as long as the sepals, slightly spreading. 
Pods spreading, not twice as long as their pedicels; valves 1-nerved ; 
style short, cylindrical. Seeds ovoid, usually not compressed, with- 
out a wing at the apex. 
On wall-tops, rocks, dry banks, and recently disturbed ground. 
Rather common, extending over the whole of Britain. 
England, Scotland, Ireland. Annual. Spring. 
Stem 3 to 18 inches high, erect, branched in the upper portion 
in the larger examples, branches ascending. Radical leaves forming 
arosette. Stem leaves scattered, distant; all the leaves vary con- 
siderably in shape and in the marginal outline, but most commonly 
the radical and lower stem leaves are remotely denticulate, and the 
upper stem leaves entire. Flowers } inch across, white. Pedi- 
cels 4 to 2 inch long. Pods 4 to # inch long, slightly curved 
upwards, more slender and convex than in any other species of the 
genus. Seeds extremely small, indistinctly punctured or roughened 
when viewed under a microscope, with the radicle lying on the 
back of one of the cotyledons and not along their edges as in all 
* The Plate is E. B. 901, unaltered. 
