220 ENGLISH BOTANY. 
SPECIES I-SENEBIERA DIDYMA. Pers. 
Puate CLIX.* 
Reich, Ic. Fl. Germ. et Helv. Vol. II. Tetr. Tab. 1X. Fig. 4209. 
8. pinnatifida, D. C. Syst. Vol. IT. p. 523. Gr. & Godr. Fl. de Fr. Vol. I. p. 154. 
Coronopus didyma, Sm. Brit. Fl. Vol. III. p. 691. 
Lepidium didymum, Zinn. Mant. XCII. Sm. Eng. Bot. No. 248. 
Petals shorter than the sepals, or none. Pods transversely 
ovoid, notched both at the base and apex, much constricted 
between the valves so as to be didymous; valves deciduous, 
roundish-ovoid, their surface with waved transverse ridges ana- 
stomosing in the middle, but not projecting in points beyond the 
margins; stigma sessile in the apical notch. 
In waste ground and on roadsides in the southern and western 
counties of England. Probably wild in Cornwall, Devon, Somer- 
set, Hants, South Wales, and Carnarvonshire; but north of the 
latter county, and on the east coast, and in a few of the inland 
counties, it cannot be considered as more than an escape from 
gardens. 
England, Ireland. Annual or Biennial. Summer, Autumn. 
Stems all lateral, procumbent, spreading, somewhat dicho- 
tomously branched towards the extremity, 6 inches to 1 foot 
long. Leaves stalked, the uppermost sessile, all deeply pinnatifid 
(almost pinnate) ; segments of the radical and lower stem leaves 
obovate or oblanceolate, divided into slender acute lobes princi- 
pally on the side directed towards the apex of the leaf, those of the 
upper leaves narrower and more entire. Inflorescence in sessile 
corymbs, one (the central axis) in the middle of the stems; the 
others opposite the leaves or in the forks of the branches. Flowers 
white, 3g inch across; petals white, not exceeding the sepals, but 
most usually absent; stamens with seldom more than 2 of the 
filaments bearing anthers. Fruiting raceme short but rather lax ; 
pedicels spreading, + to + inch long, slender. Pods 7g inch long 
by zo inch broad ; the valves containing the seeds falling off very 
readily, and then bearing some resemblance to the achenes of one of 
the Batrachian Ranunculi. Seeds pale yellowish brown, reniform, 
punctate-striate. Embryo with the lower part of the cotyledons 
in the same line as the radicle, the upper part folded over so as to 
bring the tip of the back of one of them against the radicle, much 
as in Subularia; but in that the cotyledons are straight or slightly 
* The Plate is E. B. 248, with additions by Mr. J. E. Sowerby. 
