Barbarea. | VI. CRUCIFERA. 27 
Yellow Rocket.—A perennial of short duration, stiff and erect, green and 
glabrous, sparingly branched, 1 to 2 feet high. Leaves mostly pinnate, 
with the terminal lobe large, ‘broad, and very obtuse, while the lower ones 
are few, small, and narrow ; very rarely all the lobes are narrow, or some of 
the leaves oblong and undivided, but deeply toothed at the base. Flowers 
rather small, bright yellow. Pods usually very numerous, erect or slightly 
spreading, and crowded in a long dense raceme, each one from ? to 2, or 
even 3 inches long, terminated by an erect, usually pointed style, varying 
from 1 a line to 2 lines in length. 
Hedges, or pastures and waste places, common all over Europe, in 
Russian Asia and Northern America. Frequent i in Britain. F7. spring and 
summer. It varies much in the relative size of the lobes of the leaves, in 
the size of the flowers, in the length and thickness of the pod, in the length 
of the style, etc. A form witha very short and thick style is often con- 
sidered as a different species, under the names of B. precox and B. inter- 
media, but it passes by every gradation into those which have a pointed 
style of 2 lines, and which have again been distinguished under the name 
of B. stricta. [Five forms are recognized by many botanists :— 
a. B. vulgaris proper. Flowers large, petals twice as long as the sepals, 
pods in a dense raceme, pod erect, acute, three or more times as long as their 
pedicels. Common. 
b. B. arcuata,'Reichb. Flowers large, as in a.; pods acute, large, spreading 
in very long pedicels, style slender. Rare; Armagh in Ireland. 
c. B. stricta, Andrz. Flowers smaller, pods dense erect in a narrow 
receme, style slender. Uncommon. 
d. B. intermedia, Boreau. Leaves much cut, petals twice as long as the 
sepals, pods acute erect in a dense raceme much longer than their pedicels, 
style stouter. Cultivated fields. 
e. B. precox, Br. (American Cress). Leaves pinnatifid, segments 
narrow, flowers large, pods long distant obtuse, pedicels short stout, style 
very short and stout, seeds very large. A garden escape, being an excellent 
salad. | 
IV. NASTURTIUM. WATERCRESS. 
Glabrous perennials or annuals, with the leaves often pinnate, or pin- 
nately lobed, and small white or yellow flowers. Calyx rather loose. 
Stigma capitate, nearly sessile. Pod linear or oblong, and usually curved, 
or in some species short like a sillcule, the valves very convex, with the 
midrib scarcely visible. Seeds more or less distinctly arranged in two rows 
in each cell, and not winged. Jadicle accumbent on the edge of the 
cotyledons. 
A small genus, but widely spread over the whole area of the family. It 
differs from Sisymbrium only in the position of the radicle in the embryo; 
and the white-flowered species are only to be distinguished from Cardamine 
by the seeds forming two more distinct rows in each cell of the pod. 
Pod usually half an inch long or more. 
Flowers white . : “ ° ° . : . : : . 1. XN. officinale. 
Flowers yellow . : : , : . “ . 2. NV. sylvestre. 
Pod usually 3 inch long or less. "Flowers yellow. 
Pod oblong, curved. Petals scarcely longer than the Pops . 3. WV. palustre. 
Pod ovoid, straight. Petalslongerthanthecalyx . 4 NV. amphibium., 
1. N. officinale, Br. (fig. 52). Common Wi atercress. +-Stem much 
