Japanese Knotweeds were introduced by man during the 19^th century in Europe, where they hybridized and formed a species complex now considered as “invasive”. On the basis of many herbarium specimens, the literature and archive documents, we describe the history of their discovery and introduction in France. The circumstances of their hybridization are given, as well as the reasons for the spread of the complex composed of both taxa and their polyploid hybrids. We show that after its discovery by Von Siebold, Reynoutria japonica was introduced as a single male-sterile clone in Lorraine during the early 1850s, whereas R. sachalinensis was discovered by both the French and Russians and subject to successive introductions. Our study reveals that at the end of the 19^th century, these Asiatic Knotweeds became very popular among horticulturists and botanical gardens. Their cultivation in sympatry has led to the production of their hybrid R. x bohemica, as well as interspecific hybridizations and introgressions with parental species, leading to considerable genetic diversity, escape and naturalisation.

日本Knotweeds是由人的有19人在介绍^个世纪在欧洲，他们杂交，形成复杂的物种现在被认为是“侵入”。根据许多植物标本室标本，文献和存档文件，我们描述了它们在法国的发现和引进的历史。给出了它们杂交的情况，以及由类群及其多倍体杂种组成的复合体传播的原因。我们显示，在冯·西伯德（Von Siebold）的发现下，雷诺氏菌（Reynoutria japonica）在1850年代初被引入了洛林单雄性不育克隆，而沙棘是由法国人和俄罗斯人发现的，并陆续介绍。我们的研究表明，在19月底^日世纪，这些亚洲Knotweeds成了园艺和植物园中很受欢迎。他们在共生植物中的栽培导致了其杂交R的生产。x bohemica，以及与亲本物种的种间杂交和渗入，导致相当大的遗传多样性，逃逸和自然化。