Introduction:
Common periwinkle (Vinca major)
Vinca major is introduced to new locations usually as an ornamental or medicinal herb. It spreads locally from dumped garden waste, plant fragments carried downstream and as a garden escape along shady corridors. It grows most vigorously in moist shady areas in forests, along streams and urban areas. Once established the herb competes with native vegetation by smothering all native groundcover vegetation and preventing the regeneration of trees and shrubs. Vinca major is a serious threat to the understorey of forested areas and streamside vegetation.
Description:
Vinca major is a perennial, evergreen herb with erect flowering stems (0.25-0.5m long) and trailing non-flowering stems (1m long) that roots at the node. The stems contain a milky latex and shiny, dark green leaves that are 2-3cm long, opposite, round ovate, and pinnately (having parts arranged on each side of a common axis) veined. The leaves have hairs 0.1-0.4mm long along the edges and the midribs on the upper surface. The flowers are blue to violet, 2-5cm diameter and made up of five equally sized petals.
Occurs in:
Natural forests, riparian zones, urban areas.
Distribution Map:
Common periwinkle (Vinca major) Distribution in North America shown in green.
Habitat description:
Moist shady situations will produce thickest growth. It commonly occurs along riverbanks, on silty alluvial soils, but may also appear around the edges of towns, in cemeteries and anywhere where garden refuse is dumped. V. major as being able to, grow in the deepest shade, even in poor soil. However, V. major grows most vigorously in moist soil with only partial sun. Hot, dry, or cold weather can cause the herb to die back temporarily. V. major is most commonly found around lawns, roadsides, cemeteries, and shaded waste places in moist rich soil where it has escaped. According to Bean and Russo, it often spreads from old home sites and due to it’s shade requirement, often grows in patches around the bases of trees and around drainages where dense cover is available. V. major, does better in moist areas, especially on ephemeral or permanent
Close up of Common periwinkle (Vinca major) Weed.
creeklines and river channels.
General impacts:
Vinca major forms dense stands that exclude other herbs and creates a problem in areas where it competes with native herbs. This species is a particular threat to the understory of riverine vegetation as it will spread from plant fragments carried by high flows.V. major, forms dense mats which smother all native groundcover vegetation and prevent regeneration of trees and shrubs. This can have important long term consequences on streambanks, where the eventual loss of native tree and shrub cover could lead to erosion.
Geographical range:
Native range: Mediterranean basin.
Known introduced range: Australia and the United States.
Management information:
Physical: Manual removal by raising the runners with a rake, mowing them down close to the ground, or digging them out by hand.
Chemical: Removal of stolons [the trailing branch that produces new plants from buds; a runner] by hand and spot spraying active growth with 0.25% triclopyr in water or 1% glyphosate in water” are effective control measures currently used. The most effective chemical controls are paraquat and Goal, which contain the active ingredient oxyflurfen. Other chemicals that have been proven effective are 2,4-D, 2,3,6-TBA, and Fenuron.
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