Taxonomy and evolution of the Convolvulus sabatius complex (Convolvulaceae)

Abstract

A revision of the Convolvulus sabatius complex is presented and five taxa are now recognised. Convolvulus valentinus is re-circumscribed to comprise only blue-flowered individuals. Yellow-flowered plants previously referred to this species are transferred to C. supinus where they are recognised as a distinct variety: C. supinus var. melliflorus, comb nov. Variation in intensity of flower colour, pubescence and leaf shape among blue-flowered C. valentinus is highly variable within populations and in contrast to earlier treatments, no infraspecific taxa based on these traits are recognised. Despite suggestions to the contrary, the delimitation of the cultivated ornamental C. sabatius and its two subspecies is unproblematic. Molecular data from the chloroplast trnH-psbA region support the recircumscription of C. supinus and C. valentinus and highlight the genetic distinctiveness of a disjunct Iberian population of the latter that merits further investigation.