'Transact. Hort. Soc.' volume 5 1824 page 294.) Major R. Trevor Clarke informs me that he crossed two members of the Pine class (Myatt's B. Queen and Keen's Seedling) with the wood and hautbois, and that in each case he raised only a single seedling; one of these fruited, but was almost barren. Mr. W. Smith, of York, has raised similar hybrids with equally poor success. (10/105. 'Journal of Horticulture' December 30, 1862 page 779. See also Mr. Prince to the same effect ibid 1863 page 418.) We thus see (10/106. For additional evidence see 'Journal of Horticulture' December 9, 1862 page 721.) that the European and American species can with some difficulty be crossed; but it is improbable that hybrids sufficiently fertile to be worth cultivation will ever be thus produced. This fact is surprising, as these forms structurally are not widely distinct, and are sometimes connected in the districts where they grow wild, as I hear from Professor Asa Gray, by puzzling intermediate forms.
The energetic culture of the Strawberry is of recent date, and the cultivated varieties can in most cases be classed under some one of the above native stocks. As the American strawberries cross so freely and spontaneously, we can hardly doubt that they will ultimately become inextricably confused. We find, indeed, that horticulturists at present disagree under which class to rank some few of the varieties; and a writer in the 'Bon Jardinier' of 1840 remarks that formerly it was possible to class all of them under some one species, but that now this is quite impossible with the American forms, the new English varieties having completely filled up the gaps between them. (10/107. 'Le Fraisier' par le Comte L. de Lambertye pages 221, 230.) The blending together of two or more aboriginal forms, which there is every reason to believe has occurred with some of our anciently cultivated productions, we see now actually occurring with our strawberries.
The cultivated species offer some variations worth notice. The Black Prince, a seedling from Keen's Imperial (this latter being a seedling of a very white strawberry, the white Carolina), is remarkable from "its peculiar dark and polished surface, and from presenting an appearance entirely unlike that of any other kind." (10/108. 'Transact. Hort. Soc.' volume 6 page 200.) Although the fruit in the different varieties differs so greatly in form, size, colour, and quality, the so-called seed (which corresponds with the whole fruit in the plum) with the exception of being more or less deeply embedded in the pulp, is, according to De Jonghe (10/109. 'Gardener's Chronicle' 1858 page 173.) absolutely the same in all: and this no doubt may be accounted for by the seed being of no value, and consequently not having been subjected to selection. The strawberry is properly three-leaved, but in 1761 Duchesne raised a single-leaved variety of the European wood-strawberry, which Linnaeus doubtfully raised to the rank of a species. Seedlings of this variety, like those of most varieties not fixed by long-continued selection, often revert to the ordinary form, or present intermediate states. (10/110. Godron 'De l'Espece' tome 1 page 161.) A variety raised by Mr. Myatt (10/111. 'Gardener's Chronicle' 1851 page 440.), apparently belonging to one of the American forms presents a variation of an opposite nature, for it has five leaves; Godron and Lambertye also mention a five-leaved variety of F. collina.
The Red Bush Alpine strawberry (one of the F. vesca section) does not produce stolons or runners, and this remarkable deviation of structure is reproduced truly by seed. Another sub-variety, the White Bush Alpine, is similarly characterised, but when propagated by seed it often degenerates and produces plants with runners. (10/112. F. Gloede in 'Gardener's Chronicle' 1862 page 1053.) A strawberry of the American Pine section is also said to make but few runners. (10/113. Downing 'Fruits' page 532.)
Much has been written on the sexes of strawberries; the true Hautbois properly bears the male and female organs on separate plants (10/114. Barnet in 'Hort.