A new yellow-flowered species of Centaurea (Asteraceae) from Mt Imittos, Attica, Greece

Centaurea hymettia (Asteraceae, Centaurea sect. Acrolophus) is described as a new species from Mt Imittos (Hymettus) near Athens, south-central Greece. It is the only steno-endemic of the mountain. Within the section the closest affinities are with C. laureotica, which occurs in an area ca. 30 km to the southeast. Both C. hymettia and C. laureotica are tetraploids with 2n = 36+2B and 2n = 36 chromosomes respectively.