The road beyond this rises from the valley of the Almo, and passes
over a kind of plateau. It is hemmed in on either side by high ugly
walls, shaggy with a profusion of plants which affect such situations.
The wild mignonette hangs out its pale yellow spikes of blossoms, but
without the fragrance for which its garden sister is so remarkable;
and the common pellitory, a near ally of the nettle, which haunts all
old ruins, clings in great masses to the crevices, its leaves and
ignoble blossoms white with the dust of the road. Here and there a
tall straggling plant of purple lithospermum has found a footing, and
flourishes aloft its dark violet tiara of blossoms; while bright tufts
of wall-flower send up their tongues of flame from an old tomb peering
above the wall, as if from a funeral pyre. The St. Mary thistle grows
at the foot of the walls in knots of large, spreading, crinkled
leaves, beautifully scalloped at the edges; the glazed surface
reticulated with lacteal veins, retaining the milk that, according to
the legend, flowed from the Virgin's breast, and, forming the Milky
Way in mid-heaven, fell down to earth upon this wayside thistle. Huge
columns of cactuses and monster aloes may be seen rising above the top
of the walls, like relics of a geologic flora contemporaneous with the
age of the extinct volcanoes around. But the most curious of all the
plants that adorn the walls is a kind of ivy which, instead of the
usual dark-greenish or black berries, bears yellow ones. This species
is rare, but here it occurs in profusion, and is as beautiful in
foliage as it is singular in fruit. The walls themselves, apart from
their floral adorning, are very remarkable, and deserving of the most
careful and leisurely study. They are built up evidently of the
remains of tombs; and numerous fragments of marble sarcophagi,
pillars, inscriptions, and rich sculpture are imbedded in them,
suggestive of a whole volume of antiquarian lore, so that he who runs
may read.