Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: June 13, 2025
The fact of the mutation may be very probable, but the full proof is, of course, wanting. Such is the case with the mutative origin of Xanthium commune Wootoni from New Mexico and of Oenothera biennis cruciata from Holland. The same doubt exists as to the origin of the Capsella heegeri of Solms-Laubach, and of the oldest recorded mutation, that of Chelidonium laciniatum in Heidelberg about 1600.
O. cruciata grows in the Adirondack Mountains, in the states of New York and Vermont, and seems to be abundant there. It has been introduced into botanical gardens and yielded a number of hybrids, especially with O. biennis and O. lamarckiana, and the narrow petals of the parent-species may be met with in combination with the stature and vegetative characteristics of these last named species.
The form known as O. biennis in Europe, and used by de Vries in all of the experiments described in these lectures, has not yet been found growing wild in America and is not identical with the species bearing that name among American botanists.
In all other respects it resembled wholly the biennis, especially in the pure green color of its foliage, which at once excluded all suspicion of hybrid origin with the purple O. cruciata. Moreover in our country this last occurs only in the cultivated state in botanical gardens. Intermediates were not seen, and as the plant bore some pods, it was possible to test its constancy.
This form is met with in different parts of France, while the biennis and muricata are very common in the sandy regions of Holland, where I have observed them for more than 40 years. They are very constant and have proven so in my experiments. Besides these three species, the large-flowered evening-primrose, or Oenothera lamarckiana, is found in some localities in Holland and elsewhere.
Its immediate predecessor must have been the subgenus Onagra, which is considered by some authors as consisting of a single systematic species, Oenothera biennis. Its multifarious forms point to a common origin, not only morphologically but also historically.
Intermediates are often found in hybrid cultures, and in them the character is a very variable one, but as yet they were not met with in progeny of this mutant. All these plants were exactly like O. biennis, with the single exception of their petals. Epilobium hirsutum cruciatum was discovered by John Rasor near Woolpit, Bury St. Edmunds, in England.
Concerning this matter Professor de Vries writes under date of Sept. 12, 1905: "The 'biennis' which I collected in America has proved to be a motley collection of forms, which at that time I had no means of distinguishing. No one of them, so far as they are now growing in my garden is identical with our biennis of the sand dunes." The same appears to be the case with O. muricata.
From thence they have spread into the vicinity, becoming common and exhibiting the behavior of indigenous types. Oenothera biennis was introduced about 1614 from Virginia, or nearly three centuries ago.
Hence there can be little doubt that the unpaired units are the cause of this decrease in reproductive power. The genus Oenothera is to a large degree devoid of varietal characteristics, especially in the subgenus Onagra, to which biennis, muricata, lamarckiana and some others belong.
Word Of The Day
Others Looking