Acta Horti Bergiani, Bd 7. no. 3 (1922)
Zytologische Studien über die Gattung Rosa
Gunnar Täckholm

p. 109
38. R. laxa Retz. det. Almquist. Turkestan, Dsungarei, Altai. (Kew: R. l. Siberia). Nach Almquist ist dieses Spezimen und überhaupt die ganze Art laxa als die Hybride beggeriana X cinnamomea anzusehen. Die Tetradenteilung der PMZ erfolgt regelmässig. In den Diakinesekernen können 7 Gemini gezählt werden. Ein tetraploider, auch als laxa bestimmter Strauch wird als Nr. 117 erwähnt.

"According to Almquist this specimen and indeed the whole type laxa is to be regarded as the hybrids beggeriana X cinnamomea."

"A tetraploid, certain as laxa shrub is mentioned as no. 117."

p. 130
117. R. laxa Retz. nach der Etikette in Uppsala. ALMQUIST det. laxa, welche Art nach ihm der Bastard beggeriana X cinnamomea ist. Eine diploide laxa aus Kew ist als Nr. 38 erwähnt. Ich wage es nicht zu versuchen, die Bestimmungen dieser zwei verschiedenchromosomigen Individuen zu kontrollieren, da das gepresste Material sehr unvollständig ist. Da die beiden Spezimen indessen ausserlich recht verschieden sind, wäre es sehr gut möglich, dass eines derselben keine laxa ist. Ehe die Chromosomenzahl der laxa sicher festgestellt werden kann, dürfte genau bestimmtes Material dieser wenig studierten Spezies untersucht werden. — In Diakinese- und Interkinesekernen wurde die haploide Zahl auf 14 bestimmt. Diakinesekerne mit abgeschwächter Affinität zwischen den Paarungen einiger Gemini kommen ziemlich häufig vor. Im heterotypen Metaphasenstadium kann zuweilen beobachtet werden, dass einzelne Chromosomen von der Platte ziehmlich entfernt liegen. 2 x = 28.

(This is probably R. laxa Hort.)
The Garden 36: 543 (Dec. 14, 1889)

THE STANDARD ROSE STOCK FOR THE FUTURE.
Otto Froebel, Zurich

For a number of years the growing of Roses, though always considerable, has been increasing to such an extent, that nurserymen began to be at a loss whence to get their stocks for dwarf Roses as well as standard ones. The practice has become nearly universal of raising seedlings of Rosa canina as well as the Manetti, polyantha, and other kinds for this purpose. But with all these species there are so many well-known inconveniences, that it would be most desirable to find a more suitable type for the stock.

Everywhere nurserymen try to get hold of such a species, and we also have been experimenting for upwards of ten years, choosing especially Central Asiatic kinds for the purpose of having a stock which would be perfectly hardy. The beautifully straight stems, almost thornless, of Rosa laxa (Retz) led us to suppose that this species would answer our purpose. Our attention once fixed upon it, we soon found many more qualities, which will place it above all competition for this special purpose.

While other kinds are very troublesome, through their numerous shoots rising directly from the roots, Rosa laxa never forms any suckers. The stems are not only perfectly straight and almost without thorns, but they scarcely branch out at all, and, moreover, they are very hard and firm, containing very little pith; for this reason they will withstand any amount of frost, and have proved perfectly hardy without any cover, even in the severe winters of 1870 and 1879 to 1880.

Another very important thing is the relatively short season of growth of Rosa laxa. While Rosa canina and its congeners keep growing late in autumn until frost forces them to rest, Rosa laxa will finish growing by the middle of September. In consequence the Roses budded on it are forced to rest in good time and so ripen their wood thoroughly, thus resisting frost much better and becoming far more hardy when budded on R. laxa. Roses forced to rest early in this way will of course be excellent for forcing.

Any kind of Rose takes very easily when budded on Rosa laxa. They will join firmly, while, for instance, Roses budded on the Manetti will sometimes fall off again. We possess a variety of standard Roses, as well as dwarf ones, budded two and three years ago on Rosa laxa, so as to be perfectly able to judge.

The growing of standards of Rosa laxa is very easily done. The plants should be treated just like other nursery stock, but not be cut back until the growth to be used for a stem is formed and has attained the height required. We possess large pieces of land occupied by such standards of Rosa laxa, and to a grower of Roses it would be a pleasure to walk through them and to see the clean, straight stems. While the land planted with other Rose stocks can hardly be kept clean on account of the suckers, it is easy to pass through between the rows planted with R. laxa. All these are qualities which will put Rosa laxa above any other kind of Rose for a stock. Besides, it is a nice ornamental shrub, resembling somewhat Rosa pomifera.

From the notes of Walter Schowalter, courtesy of Margit Schowalter:
Rosa laxa retzius - North Asia.
Widely planted as field hedges and game shelter. Sometimes grows more than 12 feet tall, very thorny, suckers. flowers single pink, but there are white ones. Small red hips. Not for home garden planting. Sometimes called Hansen's Hedge Rose.