233. Moreover, certain plants regularly produce neutral flowers, consisting of floral envelopes only. In Fig. [214], some are seen around the margin of the cyme in Hydrangea. They are likewise familiar in the Hobble-bush and in Wild-Cranberry tree, Viburnum Oxycoccus; where they form an attractive setting to the cluster of small and comparatively inconspicuous perfect flowers which they adorn. In the Guelder Rose, or Snow-ball of ornamental cultivation, all or most of the blossoms of this same shrub are transformed into neutral flowers.
Fig. 218. A flos plenus, namely, a full double flower of Rose.
[234.] The Essential Organs are likewise of two kinds, placed one above or within the other; namely, first, the Stamens or fertilizing organs, and second, the Pistils, which are to be fertilized and bear the seeds.
Fig. 219. A stamen: a, filament; b, anther, discharging pollen.
Fig. 220. A pistil; with ovary, a, half cut away, to show the contained ovules; b, style; c, stigma.
[235.] A Stamen consists of two parts, namely, the Filament or stalk (Fig. [219] a), and the Anther (b). The latter is the only essential part. It is a case, commonly with two lobes or cells, each opening lengthwise by a slit, at the proper time, and discharging a powder or dust-like substance, usually of a yellow color. This powder is the Pollen, or fertilizing matter, to produce which is the office of the stamen.