All botanists have described the strawberry as perfect in flower or bi-sexual. But our cultivated varieties are now classed as staminate and pistillate or pistillate and perfect. Without doubt this change has come from two main causes: (1. Seedling Variations) The cultivated plants often assume forms and show changes quite different from the natural type. (2. Seed Variation of Cultivated Plants) Hybridizing often brings about sterility in various forms. In the case of the Green Prolific, Hovey seedling, and other sorts, it is known that they were the product of a cross of two bi-sexual varieties, yet they have no perfect stamens. In such cases we know that the change was made by hybridizing, Fig. 80 at A shows the pistillate flower. If planted apart from perfect varieties no fruit will develop unless partially or wholly pollinated by bees or other insects. Fig. 80 B shows the flower of a perfect variety, with the stamens in a circle around the mass of pistils in the centre.
In planting, some growers plant one row of a perfect variety alternated with two rows of a pistillate variety.
Others alternate the rows, planting as many rows of perfect as of pistillate varieties. In private gardens the perfect and imperfect varieties are often alternated in the rows. This plan mixes the varieties in a way not desirable for furnishing plants, but favorable for perfect pollination and large and perfect berries.
Fig. 80. - A, Imperfect strawberry flower ; B, perfect flower, showing the stamens.
We now have many varieties of fine size and excellent quality with perfect flowers, but experienced growers prefer to alternate the perfect and imperfect varieties, as it is found in practice that the pistillate varieties will escape injury of the ovaries by frost when those of the staminate sorts are killed. It is also found that a frost that will blacken the ovaries of the staminate varieties will not injure the stamens. The development of pollen is an exhaustive process, hence the ovaries of the perfect varieties are not as well stored with starch, and as perfectly matured, as those of varieties that have no stamens or pollen.
Fuller says: "Strawberry culture would probably have been just as far advanced if we had never had a pistillate variety in cultivation, and much confusion would have been avoided. Had not Mr. Hovey produced so good a pistillate variety as he did, it is very likely that such kinds would never have been tolerated by fruit-growers anywhere." This may be true in some parts of the Union, but is not true in the prairie States, for the reason above given, which is well established by long experience.