Taxonomy of the genus Cytisus

Using morphometry as a tool to help define the boundaries of taxa in this genus, this study was done within the context of the Eurogeni and BRIO research programmes  (funded by the Regional Council of the Pays de la Loire and the French government, and coordinated by V. Kapusta). The aim was to redefine the boundaries of all wild taxa (section, species, subspecies, varieties, forma) related to a set of ornamental brooms, using morphometric and phenotypic methods on fresh or herbarium plants. Using more than 2000 herbarium samples conserved in 25 national and international institutions, the redefinition of these three sections of the genus Cytisus allowed us to recognise ten species and three interspecific hybrids. Within the species, up to four subspecies were recognised, as well as forma in some cases. Morphometric studies show that floral shape alone makes it possible to assign an individual to a section. However, assignation to a species implies the knowledge of stem, leaf and fruit trait. When combined with phylogeny and cultivar studies, this work makes it possible to specify the identity and relationship of cultivated material, as well as to propose a more precise choice of parents in a breeding programme.

Références :

• Auvray G., Gouron C., Malécot V. (2012). Floral morphology to discriminate taxa between and within Cytisus sect. Alburnoides, sect. Spartopsis and sect. Verzinum (Genisteae, Fabaceae). Plant Systematics and Evolution 298(10):1827-1835.
• Auvray G., Malécot V. (2013). A revision of Cytisus sections Alburnoides, Spartopsis and Verzinum (Genisteae, Fabaceae). Edinburgh Journal of Botany 70(1): 61-120.