Cochlearia.| VI. ORUCIFERZ. 39 
ovoid or shortly oblong, with a broad partition; the valves very convex. 
Seeds several in each cell, not bordered, the radicle accumbent on the edge 
of the cotyledons. 
Besides the common northern species, the genus contains several Asiatic 
and south European ones, some of them intermediate, in appearance, be- 
tween the two rather dissimilar ones here associated. ‘The pod is very 
different from that of any other British white-flowered Crucifer. 
Tall erect plant, with very large oblong radical leaves . « 1. C. armoracia. 
Low diffuse plant, the leaves small and thick ; . ° » 2 C, officinalis, 
1. ©. Armoracia, Linn. (fig. 84). Horseradish Cochlearia, Horse- 
radish.— Rootstock tapering into a long root. Radical leaves on long 
stalks, often 6 inches to a foot long, and 4 to 6 inches broad, sinuate and 
toothed at the edges, glabrous, but rough. Stems 2 to 3 feet high, erect ; 
the leaves smaller and narrower than the radical ones, the lower ones often 
deeply toothed or almost pinnatifid. Flowers small and white, in numerous 
racemes, forming a terminal panicle. Pods on slender pedicels, ovoid or 
elliptical, without any prominent nerve. Armoracia rusticana, Rupp. 
A plant of south-eastern origin, introduced by cultivation only into 
northern and western Europe. It has become perfectly naturalized in 
several parts of Britain, especially near the sea. JU, summer, The pod 
seldom comes to perfection in this country. 
2, C. officinalis, Linn. (fig. 85). Scurvy Cochlearia, Scurvy-grass.—A 
low, diffuse, quite glabrous, and somewhat fleshy annual or biennial, the stems 
seldom above 6 inches long. Lower leaves stalked, orbicular or reniform, 
entire or angularly toothed; the upper ones sometimes similar, sometimes 
ovate or oblong, and often quite sessile. Flowers in short racemes, the 
petals obovate and spreading. Pods globular or ovoid, varying from 2 to 3 
lines in diameter, pointed by the short style, the midrib of the valves very 
prominent when dry. C. polymorpha, Syme. 
In stony, muddy, or sandy soils, all around the Arctic Circle, on the 
sea-coasts of northern and western Europe, and at considerable elevations 
in the great mountain-chains of Europe. Not uncommon on the shores of 
England and Ireland, still more abundant on those of Scotland, penetrating 
inland along some of its rivers, and in the Highland mountains, 7. all 
summer, It varies much in the size and shape of the leaves, in the size of 
the flowers, and the size and shape of the pods, and has been divided into 
two, three, or even eight or nine species. [The most prominent varieties 
are— 
a. O. officinalis proper. Root-leaves orbicular or.reniform, deeply cordate, 
pods nearly globose. 
b. C. alpina, Wats. Leaves as in a, pods narrowed at bothends. C. 
greenlandica, Sm. Mountains, 
ce. C. danica, Linn, Leaves deltoid, pods as in b. 
d. C. anglica, Linn. Much larger in all its parts. Leaves oblong- 
homboid or ovate, not cordate, pods inflated, contracted at the suture. | 
XIII. ALYSSUM. ALYSSUM. 
Annuals or low branching perennials, with a hoary or short stellate down, 
and white or yellow flowers. Filaments of the stamens, or the shorter ones 
only, usually winged near the base, or thickened, or furnished with small 
