The stamens of the females vary much in their degree of
abortion; in some plants they are quite short and produce no pollen; in others
they reach to the mouth of the corolla, but their anthers are not half the
proper size, never dehisce, and contain but few pollen-grains, these being
colourless and of small diameter. The hermaphrodite flowers are strongly
proterandrous, and H. Muller shows that, whilst all the stigmas on the same
flower-head are mature at nearly the same time, the stamens dehisce one after
the other; so that there is a great excess of pollen, which serves to fertilise
the female plants. As the production of pollen by one set of plants is thus
rendered superfluous, their male organs have become more or less completely
aborted. Should it be hereafter proved that the female plants yield, as is
probable, more seeds than the hermaphrodites, I should be inclined to extend the
same view to this plant as to the Labiatae. I have also observed the existence
of two forms in our endemic S. succisa, and in the exotic S. atro-purpurea. In
the latter plant, differently to what occurs in S. arvensis, the female flowers,
especially the larger circumferential ones, are smaller than those of the
hermaphrodite form. According to Lecoq, the female flower-heads of S. succisa
are likewise smaller than those of what he calls the male plants, but which are
probably hermaphrodites.
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