Vinca

Vinca (/ˈvɪŋkə/; Latin: vincire “to bind, fetter”) is an Old World genus of flowering plants in the family Apocynaceae, The English name periwinkle is shared with the related genus Catharanthus (and with the mollusc Littorina littorea). Some Vinca species are cultivated but have also spread invasively. Additionally, some species have medicinal uses. The most spread species is Vinca minor.

Vinca plants are subshrubs or herbaceous, and have slender trailing stems 1–2 m (3+¹⁄₂–6+¹⁄₂ ft) long but not growing more than 20–70 cm (8–27+¹⁄₂ in) above ground; the stems frequently take root where they touch the ground, enabling the plant to spread widely. The leaves are opposite, simple broad lanceolate to ovate, 1–9 cm (¹⁄₂–3+¹⁄₂ in) long and 0.5–6 cm (¹⁄₄–2+¹⁄₄ in) broad; they are evergreen in four species, but deciduous in the herbaceous V. herbacea, which dies back to the root system in winter.

The flowers, produced through most of the growing season, are salverform (like those of Phlox), simple, 2.5–7 cm (1–3 in) broad, with five usually violet (occasionally white) petals joined together at the base to form a tube. The fruit consists of a pair of divergent follicles; the dry fruit dehisces along one rupture site to release seeds.