When stable trees are not enough: conflict-aware infrageneric classification in Photinia (Maleae, Rosaceae)

Nuclear analyses repeatedly recovered five candidate lineages: an early-diverging P. davidiana–P. undulata lineage and four post-davidiana lineages. However, conflict analyses showed that several backbone nodes and species-complex regions were conflict-rich, especially the P. glabra–P. prunifolia complex, whereas most species-level instability was internal to candidate lineages. Morphological and geographical evidence did not provide single-character diagnoses, but supported practical diagnosis through repeated character combinations.

We therefore recognize two subgenera and four sections in Photinia s.s.: subg. Davidianae, subg. Photinia, sect.

Photinia, sect. Serratifoliae, sect. Integrifoliae, and sect.

Loriformes. This classification separates lineage recovery from rank implementation and treats conflict as an explicit decision boundary rather than as either a reason for naming every clade or for abandoning formal classification more generally in conflict-rich and taxonomically difficult plant lineages.