Thiebaut, M. & F. Labussiere (2013). Typification of species of Betonica L. (Lamiaceae) from Jordan herbarium. Candollea 68: 285–299. In French, English and French abstracts.
Jordan's herbarium, property of the Faculté Catholique de Lyon, was deposited in 2007 in LY. Numerous sheets were sold a few years after Alexis Jordan's death, but this collection still contains a lot of unknown types, as well as many precious documents like his seeding notebooks and working notes. This allows a whole reconstitution of the experimental techniques practised by this great botanist in his garden in Lyon. In 1868, Jordan and Fourreau described 27 species of Betonica L. (Lamiaceae) in their “Breviarium Plantarum Novarum”. Our typification work, consisted in researching sheets of Betonica in Jordan's herbarium, in LY and in other European herbaria. The oldest specimen we found is of 1853 whereas the youngest is of 1890. Finally, 19 lectotypes and 6 neotypes have been identified. There are still missing samples for 2 of the 27 “jordanons”.