If
these latter bushes and the more fertile female ones were to supplant the
others, the spindle-tree would be as strictly dioecious in function as any plant
in the world. This case appears to me very interesting, as showing how gradually
an hermaphrodite plant may be converted into a dioecious one. (7/7. According to
Fritz Muller 'Botanische Zeitung' 1870 page 151, a Chamissoa (Amaranthaceae) in
Southern Brazil is in nearly the same state as our Euonymus. The ovules are
equally developed in the two forms. In the female the pistil is perfect, whilst
the anthers are entirely destitute of pollen. In the polleniferous form, the
pistil is short and the stigmas never separate from one another, so that,
although their surfaces are covered with fairly well-developed papillae, they
cannot be fertilised, these latter plants do not commonly yield any fruit, and
are therefore in function males. Nevertheless, on one occasion Fritz Muller
found flowers of this kind in which the stigmas had separated, and they produced
some fruit.)
Seeing how general it is for organs which are almost or quite functionless to be
reduced in size, it is remarkable that the pistils of the polleniferous plants
should equal or even exceed in length those of the highly fertile female plants.
This fact formerly led me to suppose that the spindle-tree had once been
heterostyled; the hermaphrodite and male plants having been originally long-
styled, with the pistils since reduced in length, but with the stamens retaining
their former dimensions; whilst the female plant had been originally short-
styled, with the pistil in its present state, but with the stamens since greatly
reduced and rendered rudimentary.
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