(Mar 2019)  
 
I consider that the wild form of a rose has only five petals, and that if a rose gives flowers with more petals, it should be regarded as an irregularly mutated plant or a cultivar. The next action I took was to look at the photo of the type specimen of Linné stored in the herbarium of the Linnean Society in London (http://linnean-online.org/4815/). The photo I saw met my expectation. The number of petals counted was between ten and fifteen, not five.
Rosa gallica is named by Carl von Linné in his book “Species Plantarum” (1753). The description given to it is very short: “ROSA foliis carinatis subtus scabris. Dalib. Paris. 145. Habitat in Gallia.” There are no comments on the number of petals, but just about the shape of leaves.
François Crépin wrote about the name of R. gallica in pp. 11-12 of his article “La question de la priorité des noms spécifiques envisagée au point de vue du Genre Rosa (The question of the priority of specific names considered from the viewpoint of the genus Rosa)” in “Extrait du Bulletin de l’Herbier Boissier” Tome V. No 3. Mars 1897. Crépin said, ‘Nous sommes donc ici devant un nom princeps tout à fait énigmatique et que l’on applique depuis longtemps à la plus belle espèce du genre en Europe. (So here we face a very enigmatic original name that has been applied for a long time to the most beautiful species of its kind in Europe.)’ and ‘Lors de la publication de la 2me édition de son Species, avait-il vu des spécimens du R. gallica sauvage à fleurs simples? C’est ce qu’il est difficile de dire, même en consultant son herbier. (When he (= Linné) published the 2nd edition of his Species (= Species Plantarum), had he seen specimens of R. gallica wild with single flowers? This is difficult to say, even by consulting his herbarium.)’....
The type specimen has absolute authority for botanists. In this case, the type specimen of R. gallica has a double flower. We should separate the wild form with single flowers from the original R. gallica described by Linné. We need a name for it, and further discussion about R. gallica var. officinalis Thory. How can we identify R. gallica var. officinalis from the R. gallica described by Linné?