Molecular Evidence on the Origin of Osmunda ×mildei (Osmundaceae)

The southern Chinese Osmunda ×mildei has been suggested to be an intersubgeneric hybrid, i.e., O. japonica (subgenus Osmunda) × O. angustifolia (subgenus Plenasium) or O. japonica × O. vachellii (subgenus Plenasium). These interpretations were based on morphological, cytological, and/or chloroplast DNA data, yet the parents of the hybrid remained unclear. Molecular phylogenetic relationships inferred here from chloroplast rbcL sequences and three nuclear DNA markers show that O. ×mildei is most likely a hybrid between the paternal O. japonica and the maternal O. vachellii.