CRUCIFER A. 181 
The absence of a creeping rhizome, the smaller flowers, and 
short thick pod, distinguish this from the last species, which has, 
moreover, the segments of the leaves usually narrower and less 
distinctly toothed. 
Marsh Yellow Cress, Annual Yellow Cress or Rocket, Marsh 
Nasturtium, Small Jagged Water Radish. 
French, Cresson des Marais. 
SPECIES IV—NASTURTIUM AMPHIBIUM. R. Brown. 
Puate CXXVITI.* 
Reich. Ic. Fl. Germ. et Helv. Vol. II. Zetr. Tab. LI. LII. Fig. 4363. 
Armoracia amphibia, “Koch.” Bab. Man. Brit. Bot. ed. v. p. 31. Hook. & Arn. Brit. 
Fl. ed. viii. p. 28. 
Roripa amphibia, Bess. Gr. & Godr, Fl. de Fr. Vol. I. p. 126. 
Sisymbrium amphibium, Linn. Sm. Eng. Bot. No. 1840. 
Rootstock stoloniferous, but not creeping. Leaves elliptical 
or oblanceolate, usually toothed or entire, more rarely pinnatifid. 
Petals about twice as long as the sepals, yellow. Pods ovoid or 
oblong, one half to one quarter the length of the pedicels; valves 
without a dorsal nerve; style about equal to the width of the pod. 
Seeds in 2 rows in each cell of the pod. 
In damp places, especially by river sides, and in ditches. Rather 
rare, though found in most of the counties of England; its 
occurrence.in Scotland is doubtful. 
England, Scotland? Ireland. Perennial. Summer, Autumn. 
Stem erect, 2 to 4 feet high, slightly branched. Leaves atte- 
nuated at the base, with the margin entire, serrated, or with pro- 
jecting teeth, and occasionally the leaves are pinnatifid, especially 
when growing under water; the base of the leaves is frequently 
semi-amplexicaul, with acute auricles. Flowers bright yellow, 
about + inch across, with the sepals spreading. Fruit pedicels 
spreading horizontally or a little deflexed, from } to $ inch long. 
Pods, including the style, about 4 inch long; the length of the 
valves not exceeding twice their breadth, and sometimes less. 
Seeds small, roundish oblong, somewhat angular, slightly com- 
pressed, reddish brown, punctured. Whole plant dark green, 
glabrous. 
This and the last species have been separated from the other 
plants of the genus on account of the pod being a silicula rather 
than a siliqua; but the division is an unnatural one, and has no 
* The Plate is E. B. 1840, with pods added by Mr. J, E. Sowerby. 
