In the case of
Pontederia, the ovarium includes only a single ovule, and what the meaning of
the difference in size between the pollen-grains from the corresponding sets of
anthers may be, I will not pretend to conjecture.
The clear evidence that the species just described is heterostyled and
trimorphic is the more valuable as there is some doubt with respect to P.
cordata, an inhabitant of the United States. Mr. Leggett suspects that it is
either dimorphic or trimorphic, for the pollen-grains of the longer stamens are
"more than twice the diameter or than eight times the mass of the grains of the
shorter stamens. Though minute, these smaller grains seem as perfect as the
larger ones." (4/16. 'Bulletin of the Torrey Botanical Club' 1875 volume 6 page
62.) On the other hand, he says that in all the mature flowers, "the style was
as long at least as the longer stamens;" "whilst in the young flowers it was
intermediate in length between the two sets of stamens;" and if this be so, the
species can hardly be heterostyled.
CHAPTER V.
ILLEGITIMATE OFFSPRING OF HETEROSTYLED PLANTS.
Illegitimate offspring from all three forms of Lythrum salicaria.
Their dwarfed stature and sterility, some utterly barren, some fertile.
Oxalis, transmission of form to the legitimate and illegitimate seedlings.
Primula Sinensis, Illegitimate offspring in some degree dwarfed and infertile.
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