- Name also: Dwarf Periwinkle, Common Periwinkle, Small Periwinkle, Myrtle, Creeping Myrtle
- Family: Dogbane Family – Apocynaceae
- Growing form: Perennial dwarf shrub.
- Height: 20–40 cm (8–15 in.). Stem limp, rooting, flowering branches usually ascending. Forming mat-like stands.
- Flower: Corolla regular (actinomorphic), funnel-shaped, blue–violet (sometimes white), 2.5–3 cm (1–1.2 in.) wide, fused, 5-lobed, lobes obliquely blunt. Sepals 5, glabrous. Stamens 5. Gynoecium fused, 2 carpels. Flowers solitary in axils.
- Leaves: Opposite, short-stalked, overwintering. Blade narrowly elliptic–lanceolate, round-shaped or wedge-shaped base, with entire margin, glabrous, shiny.
- Fruit: Elliptic follicle, 2 together. 3–5 rather big seeds in each follicle.
- Habitat: Ornamental, quite often an escape from cultivation, gardens, parks, urban woods, broadleaf woods, wasteland, roadsides.
- Flowering time: May–June.
Lesser periwinkle is a dwarf shrub, but at least some garden enthusiasts are of a mind to see it as a perennial. The species is one of the best evergreen ground covers that are able to grow in Finland. Many variants have been developed of this highly popular plant, including a white-flowered form. Lesser periwinkle thrives in shady places under trees and bushes. It often does well in the same place year after year, looking impressive despite requiring a lot of care, even though the garden might have gone wild and other species on the flower bed succumbed to the competition.
Periwinkles in the wild grow in and around leafy forests and are apt to escape in Finland too. Lesser periwinkle flowers early in the spring, but it is probably most noticeable in the winter when other plants have withered and its dark green shoots thread their way through the debris.
Name also: Bigleaf Periwinkle, Large Periwinkle, Blue Periwinkle
Small genus Periwinkle has around half a dozen species, most of which grow in southern Europe. Greater periwinkle, which is cultivated as a house-plant, grows casually in Finland too, close to habitation. The species cannot however survive the Finnish winter, so it stays outside for short periods only.
The genus also used to include Madagascar periwinkle (Catharanthus roseus), which is a popular perennial in southern countries, and is sometimes grown in Finland as a house plant. Apart from its ornamental properties it has forged a reputation for its alkaloids, which have been used as an efficient treatment for leukaemia.