Rubus semiplenus (Rosaceae), a new species with naturally occurring semi-double flowers from Hunan, China

The semi-double (semiplenus) floral trait is highly valued in the field of horticulture, yet it remains exceptionally rare in wild plants. Rubus semiplenus, a new species with naturally occurring semi-double flowers, is described and illustrated. This new species was discovered in the Nanyue Hengshan National Nature Reserve, Hunan Province, China.

It is distinguished by its herbaceous to dwarf subshrub habit, simple suborbicular leaves (0.7–2.5 × 0.7–2.5 cm), and semi-double flowers with dicyclic petals (10–12). Molecular phylogenetic analyses based on ITS and rbc L + mat K sequences consistently confirmed that R. semiplenus belongs to Sect. Rosaefolii as defined by Focke and is closed to R. hirsutus.