Osmanthus dechangensis (Oleaceae), a new and rare species from Sichuan, China

We describe and illustrate Osmanthus dechangensis J.L.Liu & Y.Yuan, a new species within the Oleaceae family, endemic to Sichuan, China. This evergreen shrub or tree is characterized by inflorescences clustered in the leaf axils and at branch tips. The leaves, which are either entire or exhibit spiny serrations, are complemented by bracts that are hairy or ciliate along the margins. The species is dioecious, bearing separate male and hermaphroditic flowers. While O. dechangensis shares some similarities with O. yunnanensis and other closely related species, it bears distinct morphological traits, including glabrous young twigs and larger leaves measuring (6.5–)8.2–23.3 cm in length, with (8–)10–25 pairs of lateral veins. The cymose inflorescences are supported by a peduncle of (0.5–)1–3 mm in length and feature more bracts, arranged in (5–) 6–8 layers with (10–) 12–16 individual bracts. The flowers are larger, with the calyx measuring 1.5–2 mm in length, the corolla 6–7 mm long, featuring a corolla tube of 1–2 mm and lobes measuring (4.5–)5–6 mm in length. The stamens are inserted near the mouth of the corolla tube. The filaments are partially fused to the corolla tube for about 2 mm, extending freely for 2.5–3.5 mm, with anthers measuring (2.5–)3–3.5 mm in length. In hermaphroditic flowers, the connectives do not protrude, while in male flowers, they extend slightly as a small apical projection. The species' distinct flowering period, from January to February, further differentiates it from closely related taxa.