The Hybrid Origin of Emilia praetermissa (Senecioneae: Compositae)

Interspecific hybrids were obtained between Emilia coccinea(n = 5) and E. sonchifolia (n = 5). Except for quantitativecharacters such as plant size, head size, and leaf size, thediploid hybrid was similar to E. praetermissa (n = 10). Artificial polyploidization of the diploid hybrid resulted inan allotetraploid which is morphologically indistinguishablefrom E. praetermissa. The artificial tetraploid hybrid and E.praetermissa are also similar with respect to their karyotypesand their meiotic behaviours. Morphological and cytogenetic evidence suggest that E. praetermissaoriginated from a plant which is of hybrid origin and whichis similar to the synthetic tetraploid.