A most curious terminal pelory is that of the common foxglove or
_Digitalis purpurea_. As we have seen in a previous lecture, it is an
old variety. It was described and figured for the first time by Vrolik
of Amsterdam, and the original specimens of his plates are still to be
seen in the collections of the botanic garden of that university. Since
his time it has been propagated by seed as a commercial variety, and may
be easily obtained. The terminal flower of the central stem and those of
the branches only are affected, all other flowers being wholly normal.
Almost always it is accompanied by other deviations, among which a
marked increase of the number of the parts of the corolla and other
whorls is the most striking. Likewise supernumerary petals on the outer
side of the corolla, and a production of a bud in the center of the
capsule may be often met with. This bud as a rule grows out after the
fading away of the flower, bursting through the green carpels of the
unripe fruit, and producing ordinarily a secondary raceme of flowers.
This raceme is a weak but exact repetition of the first, bearing
symmetrical foxgloves all [484] along and terminating in a peloric
structure. On the branches these anomalies are more or less reduced,
according to the strength of the branch, and conforming to the rule of
periodicity, given in our lecture on the "five-leaved" clover. Through
all this diminution the peloric type remains unchanged and therefore
becomes so much the purer, the weaker the branches on which it stands.
I am not sure whether such peloric flowers have ever been purely
pollinated and their seed saved separately, but I have often observed
that the race comes pure from the seed of the zygomorphic flowers. It is
as yet doubtful whether it is a half race or a double race, and whether
it might be purified and strengthened by artificial selection. Perhaps
the determination of the hereditary percentage described when dealing
with the tricotyls might give the clue to the acquisition of a higher
specialized race. The variety is old and widely disseminated, but must
be subjected to quite a number of additional experiments before it can
be said to be sufficiently understood.
The most widespread peloric variety is that of _Gloxinia_. It has erect
instead of drooping flowers; and with the changed position the structure
is also changed. Like other pelories it has five equal stamens instead
of four unequal [485] ones, and a corolla with five equal segments
instead of an upper and a lower lip. It shows the peloric condition in
all of its flowers and is often combined with a small increase of the
number of the parts of the whorls. It is for sale under the name of
_erecta_, and may be had in a wide range of color-types. It seems to be
quite constant from seed.
Public-domain text, read in full here on John Shaqi.
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