ANGIOSPERMS, 
535 
in a flower, making the plant uniaxial. When this is the case a sympodial or 
cymose inflorescence is usually developed, new axes with terminal flowers arising 
beneath the first flower; but it is more common for only axes of the second, 
third, or a higher order to terminate in a flower, so that the plant may in this 
respect be termed bi-, tri-, or multi-axial. 
While in Gymnosperms the flowers are typically unisexual or diclinous, herma- 
phroditism largely prevails among Angiosperms, although monoecious and dioecious 
species, genera, and families are not uncommon. The male flowers are sometimes 
essentially diff'erent in structure from the female flowers (as in Cupuliferae and 
Cannabineae), but in most cases the unisexuality arises merely from the partial or 
entire abortion either of the androecium or the gynoeceum, the flower being in other 
respects constructed on the same type (Fig. 357, A); and in such cases it also 
frequently happens that hermaphrodite flowers are developed in addition to the 
male and female (polygamous species, as the Ash, Acer, Saponaria ocymoides, &c.). 
But even in the greater number of cases where the male and female organs are 
completely developed in hermaphrodite flowers and functionally perfect, fertilisation 
Fig. 358 .—Asaritm canadoise; A the flower cut through lengthwise, p the perianth ; B horizontal section of the flower 
above the ovary ; C horizontal section of the sex-locular ovary ; D a stamen with its lateral anther-lobes a. 
takes place by the conveyance of the pollen of one flower to the gynaeceum of 
other flowers or even of other individuals of the same species, because either polli- 
nation within the same flower is impossible in consequence of special contrivances 
(such as dichogamy), or because the pollen is potent only in the fertilisation of 
ovules of another flower (as in Orchidese, Corydalis, &c.). To these phenomena 
we shall recur more in detail in the Third Book, when speaking of the physiology 
of sexual reproduction. 
While in Gymnosperms the üoral axis is usually elongated to such an extent 
that the sexual organs, especially if numerous, are evidently arranged one above 
another in alternate whorls or in spirals, — in Angiosperms, on the contrary, the 
floral axis which bears the floral envelopes and sexual organs is so abbreviated 
that space can only be found for the various foliar structures by a corresponding 
expansion or increase in size of the receptacle or torus ; this receptacle swells even 
before and during the formation of the floral leaves in a club-shaped manner, and is 
not unfrequently expanded flat like a plate or even hollowed out like a cup in such a 
manner that the apex of the axis is placed at the bottom of the hollow ([). 220), while 
