(
32
)
opinion, that in a complete flower, whose parts are definite, the number of stamina and also of pistilla is equal to that of the divisions of the calyx and corolla
united in Dicotyledones, and of both series of the perianthium in Monocotyledones.
This assumed complete number of stamina is actually the prevailing number in Monocotyledones; and though in Dicotyledones less frequent than what
may be termed the symmetrical number, or that in which all the series are
equal, is still found in decandrous and octandrous genera, and in the greater
part of Leguminosae. The tendency to the production of the complete number, where the symmetrical really exists, is manifested in genera belonging
or related to those pentandrous families in which the stamina are opposite to
the divisions of the corolla, as by Samolus related to Primulaceae, and by Baeobotrys, having an analogous relation to Myrsineas ; for in both these genera, five
additional imperfect stamina are found alternating with the fertile, and consequently occupying the place of the only stamina existing in most pentandrous
families. Indications of this number may also be said to exist in the divisions
of the hypogynous disk of many pentandrous orders.
With respect to the Pistilla, the complete number is equally rare in both
the primary divisions of phasnogamous plants. In Monocotyledones, the symmetrical number is very general, while it is much less frequent in Dicotyledones, in which there is commonly a still farther reduction.
Where the number of Pistilla in Dicotyledones is reduced to two, in a flower
in which both calyx and corolla are present and their division quinary, one of
these pistilla is placed within a division of the calyx, the other opposite to a
petal or segment of the corolla. In other words, the addition to the solitary
pistillum, (which is constantly anterior or exterior), is posterior or interior.
This is the general position of the component parts of a bilocular ovarium, or an
ovarium having two parietal placentas; and in flowers whose division is quinary,
I can recollect no other exceptions to it, than in some genera of Dilleniacese.
It is particularly deserving of notice, that the common position of the cells
of the bilocular pericarpium with relation to the axis of the spike was well
known to Ctesalpinus, who expressly distinguished Cructferce from all other
bilocular families by their peculiarity in this respect, the loculi in that family
being placed right and left, instead of being anterior and posterior*.
* Ccesalp.
de Planti.s,
p. 327. cap. xv. et p. 351. cap. liii.