ESSENTIAL ORGANS OF REPRODUCTION.—ANDRECIUM. 241 
flower possesses neither andrcecium nor gyncecium, as is some- 
times the case with the outer florets of the capitula of the Com- 
ositze, it is said to be newter. When the flowers are unisexual 
both staminate and pistillate flowers may 
be borne upon the same plant, as in the Fic. 503. 
Hazel, Oak, Cuckoo-pint (jig. 403), and the 
species of Carex, in which case the plant is 
stated to be monecious; or upon different ; 
plants of the same species, as in the Willows i 
(figs. 415 and 416), when the plant is said to i 
be diwcious. In some cases, as in many Palms it 
and in the Pellitory (Parietaria), staminate, ES Hii 
pistillate, and hermaphrodite flowers are situ- IN] iti 
ated upon the same individual, and then the 
plant is called polygamous. 
Like the sepals and petals, the stamens _ || 
and carpels are considered as homologous 
with leaves, but they generally present much 
less resemblance to these organs than the 
component parts of the floral envelopes. 
Their true nature is shown, however, by 
their occasional conversion into leaves, and 
by other circumstances, which will be de- 
scribed hereafter when treating of theGeneral _ uf 
Morphology of the Flower. C Maine auseetohn 
species of Carex. The 
filaments are long 
1, THE ANDRECIUM. and capillary, and 
the anthers pendu- 
The andreecium, or male system of _lousand innate, 
Flowering Plants, is the whorl or whorls of 
organs which, in a complete flower, is situated between the 
corolla (fig. 522) or perianth (jig. 28) on the outside. and the 
gyneecium on the inside; or it is placed between the calyx 
and gynoecium when the corolla is absent (jig. 29), as in 
monochlamydeous flowers; or in achlamydeous flowers, it is 
either outside the gyncecium (jig. 30) when those flowers are 
bisexual, or it stands alone (jig. 34) when the flowers are uni- 
sexual and staminate. It is composed of one or more parts 
termed Stamens. Kach stamen consists generally of a thread- 
like portion or stalk, called the filament (fig. 27, f), which is 
analogous to the petiole of the leaf ; and of a little bag or case, 
a, which is the representative of the blade, called the anther, 
and which contains a powdery, or more rarely waxy, matter, 
termed the pollen, p. The only essential part of the stamen, 
however, is the anther with its contained pollen; but in rare 
cases the pollen is absent, and as the stamen cannot then perform 
its special functions, it is said to be abortive or sterile (fig. 
517, ls) ; in other cases it is termed fertile. It not unfrequently 
happens that flowers contain sterile filaments, that is, filaments 
me 
