Page:Popular Science Monthly Volume 62.djvu/499

Rh fertilization. The plant is purely feminine. Male or hermaphrodite specimens I never saw, though I have often cultivated hundreds of roundheads. On account of the broad leaves, and thick buds, Oenothera lata was chosen as the systematic name.

Encouraged by these results, I continued my investigation, partly, during the same year, by a closer study of the locality where the seed was collected, partly by sowing experiments on a large scale in the spring of the year following. The former made me acquainted with two new types, which had remained unobserved in 1886, but which, as rosettes of root-leaves, must have been present at the time, since Oenothera Lamarckiana is, in that locality, biennial, with hardly any exception. The one was glabrous, more delicate and more graceful, but as robust as the common form, the other had so short a style that the stigma, instead of protruding far above the stamens, was situated at the base of the flower. Both forms were formerly absolutely unknown, and, later on, in the sowing-experiments, proved to be as constant and true to seed as the mother species. That they originated in the locality where they were found may be considered as certain, but how this happened could not be investigated.

The seed, sown in the spring of the following year, again yielded two new forms. The one was a dwarf form, such a one as occurs from time to time among all kinds of culture plants—but a few decimeters high, whereas the mother species attains a height of 1 to 2 meters and more. The other was a form with shiny leaves, about half the size of Oenothera Lamarckiana, narrow, dark green, and very graceful. Both were quite fertile and produced a large quantity of seed.

Dwarf forms are ordinarily described along with the species to which they belong, as varietas nana or nanella, and my dwarf forms agree with them in every respect. They offer a good contrast with the other types, which cannot be termed varieties in the ordinary sense. For, in the first place, they deviate from the parent species not in a single character, but in all, and, in the second, they do not have their parallel in other genera. For repetition, such as appearance of white flowers, glabrous leaves, thornless stems and fruits, unbranched stems, variegated leaves, double flowers, etc., is one of the most common characteristics of true varieties.

Later the dwarfs proved to be constant to seed. Not so the shiny variety. Though I did not sow the latter each year, I did it frequently; its characters reappeared as a rule in but about one third of the individuals.

By sowing I obtained in 1888 nearly 15,000 plants, among which there were five dwarfs and five latas, that is to say, of each about 1 on every 3,000. In later years, when I became familiar with the most favorable methods of treatment, the percentage increased considerably,