. A practical course in botany, with especial reference to its bearings on agriculture, economics, and sanitation. Botany. 341 342 Figs. 341,342.— Unisexual flowers of wil- low : 341, staminate; 342, pistillate. shown that the first step taken by the breeder to secure this result is to render the flower incapable of self-fertilization, by removing the stamens. Nature ac- complishes the same purpose by the more effectual expedient of providing imper- fect, or unisexual flowers, in which sta- mens only, or pistils only, occur in the same flower. When the stamens alone are present, the flower is
. A practical course in botany, with especial reference to its bearings on agriculture, economics, and sanitation. Botany. 341 342 Figs. 341,342.— Unisexual flowers of wil- low : 341, staminate; 342, pistillate. shown that the first step taken by the breeder to secure this result is to render the flower incapable of self-fertilization, by removing the stamens. Nature ac- complishes the same purpose by the more effectual expedient of providing imper- fect, or unisexual flowers, in which sta- mens only, or pistils only, occur in the same flower. When the stamens alone are present, the flower is said to be stam- inate, or sterile, because it is incapable of producing seeds of its own, though its pollen is a necessary factor in seed pro- duction. If, on the other hand, the ovary is present and the stamens absent, the flower is pistillate and fertile; that is, capable of produc- ing fruit when impregnated with pollen. Sometimes both stamens and pistils are wanting, as in the showy corollas of the garden "snowball," the hydrangea, and the rays of the sunflower. Such blossoms': are said to be neutral, from the Latin word neuter, mean- ing neither, because they have neither pistils nor stamens. They can, of course, have no direct part in the production of fruit, but are for show merely. (231.) 268. Monoecious and dioecious plants. — When both kinds of flowers, staminate and pistillate, are borne on the same plant, as in the oak, pine, hickory, and most of our common forest trees, they are said to be monoecious, a word which means " belonging to one household"; when borne on sepa- rate plants, as in the willow, sassafras, and black gum, they. Fig. 343. — Twig of oak with both kinds of flowers: /, fertile flowers; s, a, staminate; u, pis- tillate flower, enlarged; 6, verti- cal section of pistillate flower, enlarged; c, portion of one of the sterile aments, enlarged, showing the clusters of Please note that these images are extracted from s
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