The genus Guizotia belongs to the family of Compositae, tribe Heliantheae, subtribe
Coreopsidinae. A taxonomic revision of the genus based on the morphological traits
was presented by Baagøe (1974). She reduced the number of species within the genus
Guizotia to six: G. abyssinica (L. f.) Cass.; G. scabra (Vis.) Chiov. subsp. scabra and subsp.
schimperi (Sch. Bip.) Baagøe; G. arborescens I. Friis; G. reptans Hutch; G. villosa Sch. Bip.
and G. zavattarii Lanza. Guizotia scabra contains two subspecies, scabra and schimperi.
Guizotia scabra subsp. schimperi, known locally as ‘mech,’ is a common annual weed in
Ethiopia. There is a controversy on the taxonomical category of G. abyssinica and
G. scabra subsp. schimperi (Murthy et al. 1995). Guizotia abyssinica and G. scabra subsp.
schimperi are morphologically very similar, they are both annuals, and are attacked by
the same pests and diseases. Both species have 2n=30 chromosomes with a similar
karyotype. The hybrid between G. abyssinica and G. scabra subsp. schimperi is fertile and
forms 15 bivalents in 95% of the pollen mother cells. Indeed, G. scabra subsp. schimperi is
closer to the G. abyssinica than to the perennial G. scabra subsp. scabra. On the basis of
cytological evidence, Murthy et al. (1995) proposed that the two species G. abyssinica
and G. scabra subsp. schimpri be merged into one species