difference, and having accordingly referred each plant to
both species, according to the state in which the specimen
was gathered. The erect kind, which is almost constantly
spinous, is certainly the O. antiquorum of Linnaeus, and
ought therefore to retain that name. The species here
figured is usually unarmed in spring, but more or less
prickly in autumn, and includes without doubt Linnaeus’s
O. repens, which I cannot even consider as a well marked
variety. Of his O. spinosa there is no authentic specimen;
but he appears to have first given that name to this plant,
and to have afterwards (Syst. Nat. cd. 12.) changed it to
O. arvensis, and it is probably by mistake that Murray
in the 14th edition of the Systema Vegetabilium inserted
both O. arvensis and O. spinosa. I do not think that Linnaeus
ever intended to include the erect species (as Smith
has done) in his O. arvensis, for he constantly retains it as
a distinct plant under the name of O. antiquorum.
The wild specimen figured in the plate before us was
communicated by the Right Hon. Lady Arden, W'ho for
several years past has found both this and the O. antiquorum,
when removed from the vicinity of Epsom into the
garden at Nork Park, to be permanent in their characters
and highly ornamental. O. arvensis occurs not unfre-
quently, at least in the South of England, on grassy banks
in a chalky soil, and in loose sand on the sea-shore in various
places.
Although the O. arvensis is a very distinct species from
the O. antiquorum, with which it is impossible to confound
it when seen growing, yet it is difficult to give any positive
characters by which the two plants can be readily distinguished
in herbaria. The stems of the O. arvensis are
prostrate and creeping, with ascendant branches, which are
usually unarmed, although they occasionally degenerate
into spines, especially at the end of summer and in luxuriant
specimens grown in a dry and hot situation. Every part
of the plant, but particularly the young shoots, is covered
with glandular hairs intermixed with others usually longer
and not glandular; the latter are frequently arranged on
the stem, below the insertion of the stipules, in one or two
opposite rows, as has been observed of the short hairs of
the O. antiquorum. The lower leaves have three leaflets,
the upper ones but one; these leaflets are broader, less
rigid and larger in proportion to the other parts of the
plant than in the O. antiquorum, those of the flowering
branches especially are more numerous and apparent, being
usually as long or longer than the calyx. The calyx is
longer in proportion to the flower, and shorter in proportion
to the fruit, and always much more hairy. The corolla
is usually rather smaller. The seed-pods are about the
length of the calyx, and hairy. The seeds covered with
more distant and more prominent granules. The spinous
specimens of this species which I have from various countries
do not in any other respect differ from those w'hich
are unarmed ; and as I have frequently observed the same
plants which have flowered entirely unarmed in spring,
acquire the spines by the end of the year, I cannot consider
the two states of the plant even as distinct varieties.
The O. antiquorum of Linnaeus, which is figured in Engl.
Hot. v. 10. t. 682. under the name of O. arvensis, has the
stems nearly erect, with divaricate branches. It is usually
glabrous, or covered only with a very short down, with the
exception of a single or double line of hairs down the young
branches; these hairs are by no means constant, and never
so long as in the O. arvensis, but much more apparent, on
account of the extreme shortness or total absence of the
general down of the plant; and this is probably the cause
of Wallroth’s mistake, in considering the presence or absence
of these hairs as a characteristic difference between
the two species. The leaves, especially those of the flowering
branches, are much smaller in the O. antiquorum than