I0O THE FLOWERING PLANT. 
the filaments is a glandular projection or nectary. The female 
catkins are green, and a female flower corresponds to the above 
description, except that, instead of two stamens, there is a pistil 
formed by two cohering carpels. 
Nettle.-—There are two common British forms, the small and 
the large, which are moneecious and dicecious respectively. The 
latter kind is easily recognized by its greater size and by its 
elongated paniculate inflorescences. The small male flowers have 
a four-lobed calyx, superposed to which is a whorl of four stamens. 
A minute knob, representing an aborted pistil, is seen in the 
centre. The female flowers possess a pistil, composed of a single 
carpel, but no traces of stamens. 
Hop.—The minute male flowers are arranged in cymes. Hach 
consists of a whorl of five sepals, with five superposed stamens. 
The female inflorescences are short broad catkins, the large over- 
lapping bracts of which give a cone-like appearance. They form 
the “hops” of commerce. A pair of female flowers are situated 
in the axil of each bract. Their perianth is rudimentary, and 
encloses a pistil formed of two united carpels. 
Ash.—The small flowers are borne in short racemes, and are 
without perianth. The Uiserual ones are provided with two pur- 
plish-black stamens and a pistil of two united carpels The male 
and female flowers are similar; but in one case stamens, in the 
other carpels, only are present. This is a very interesting case 
of reduction, for in the flowering ash, a South European species, 
all the flowers are bisexual, and possess four sepals and four 
petals, as well as stamens and carpels. This is also the case in 
the flowers of privet and lilac, both allied forms. 
Cohesion.—The pistil is said to be apocarpous when its con- 
stituent carpels are free. In buttercup, for example, the small 
green bodies in the centre of the flower are separate carpels (fig. 
30); here they are very numerous. Instances of smaller numbers 
are found in columbine (five), larkspur (generally three), and gorse 
or pea (one). Much more frequently the pistil is syncarpous, its 
carpels being united, as already alluded to in willow, ash, and 
hop. The union may be more or less complete. Hxamine the 
flower of a saxifrage, such as London pride. <A deeply bilobed 
pistil will be found, evidently consisting of two carpels. In pink 
or carnation the seed-containing part (ovary) is undivided, but 
projecting from the top of this are two curved threads (styles), 
which point to the presence of a pair of carpels. The same thing 
is indicated by the forked end of the style in dead nettle, sage, 
and most grasses (fig. 50). In the white lily the existence of 
three carpels can be recognized by the trilobed stigma, and the 
three compartments seen in a cross-section of ovary (fig. 38). 
