Blue Periwinkle

Vinca major L.

Synonyms - Vinca rosea.

Family: Apocynaceae.

Names:

Vinca is from the Latin pervinca meaning periwinkle and is derived from the Latin vinco meaning 'I conquer' referring to its aggressive nature.
Major means large.
Blue Periwinkle because it has blue flowers and is from the Periwinkle family.

Other names:

Greater Periwinkle
Madagascar Periwinkle.

Summary:

Blue Periwinkle is a sprawling ground-cover with hairless, dark green opposite leaves that are 20-70 mm long with a rounded base, tapering tip and have a shiny and darker upper surface. The single long-stalked flowers are blue to violet with a white throat. The flowers are 30-50 mm in diameter and tubular with 5 radiating petal lobes that are somewhat diamond shaped. Each flower has 5 stamens hidden within the flower tube.
This garden escape is sometimes found invading damp shady areas such as creek lines in disturbed woodland and paddocks. The plants are able to cover large areas by producing roots where the stems contact the ground. It is native to the Mediterranean region and widely cultivated in Australia. It flowers mainly from winter to early summer but occasional flowers may be found at most times of the year.
It can be toxic to stock.

Description:

Cotyledons:

Two.

Leaves:

Opposite pairs at right angles to the stem and at right angles to the pair below.
Stipules - None.
Petiole - 4-12 mm long with 2 small glands on the edges.
Blade - Dark green or variegated, egg shaped to broadly egg shaped or oval, shiny, 20-80 mm long x 15-50 mm wide, smooth edged. Hairs up to 1 mm long on the edges. Tip pointed. Edges curved. Base slightly indented to squarish to tapering. Surface hairless, glossy and usually a lighter green on the underside.

Stems:

Green to reddish green, low lying, up to 2500 mm long x 2-4 mm diameter, tough, often grow straight up, arch over then run along the ground and take root. Woody at the base. Milky sap. Hairless.
Flower stem - Erect or upward bending, stiff, up to 300 mm tall with 8-20 pairs of leaves.

Flower head:

Single flower on a stalk (pedicel) 20-40 mm long, which is shorter than the leaf and arises from a leaf axil

Flowers:

Blue or rarely white, 5 petalled, 20-50 mm diameter and wheel shaped with a central tube.
Ovary - Superior. Style swollen at the top with a 5 angled stigma on a crown of hairs. 2 distinct carpels. 2 nectary scales.
Style - Head with a circular tuft of hairs above the thickened ring.
Sepals - 5, overlapping, split almost the base, narrowly triangular, 10-17 mm long. Hairs 0.5-1 mm long on the edges. 2 glands on edges.
Petals - Blue or purple rarely white, funnel shape, 25-50 mm diameter, tubular, 5 spreading, egg shaped lobes, 12-20 mm long, with rounded tips and squarish or angular at the ends. In the bud they are overlapping and twisting anticlockwise. Tube 13-18 mm long, hairy on the inside near the top. A low ridge connects lobes at the throat. Hairy zone above where stamens attach.
Stamens - 5. Attached near the middle of the petal tube and enclosed. Alternate with the petals. Filaments short, bent sharply at the base and hairy at the base.
Anthers - 2 celled, free with flap-like appendage. Hairy

Fruit:

Erect. Usually 2, cylindrical to oval dry fruits (follicles) 20-50 mm long x 10 mm wide tapering at each end, at an angle to each other and joined at the base, opening by a single split with 3-8 seeds.

Seeds:

7-8 mm long, hairless and wingless. Embryo straight. Seed is rarely viable in Australia.

Roots:

Extensive and initially fibrous then developing woody crowns.
Stems form roots at the tips and some nodes.

Key Characters:

Perennial herb.
Creeping stems.
No spines at the nodes.
Leaves opposite.
Flowers solitary in leaf axils.
Corolla lobes, twisted imbricate in bud, blue or white.
Calyx 10-17 mm long.
Adapted from J.M. Black, B.L. Rye and Gwen Harden.

Biology:

Life cycle:

Perennial. It rarely establishes from seed. Stem fragments take root and form sterile shoots that grow 2-4 m in the season. Upright fertile shoots are formed at the swollen nodes and have 8-20 pairs of leaves and rarely form roots at their nodes. The fertile shoots form flowers mainly from July to November but occasional flowers can usually be found at most times of the year. It spreads rapidly in shaded conditions. It may be totally defoliated by frost but quickly recovers from dormant buds.

Physiology:

Contains alkaloids that were thought to cure diabetes and commercial preparations were made from it.
Tolerates drought and salt.
Tolerates shade.
Temperatures below -10 to -150C usually kill it.
It is defoliated by frost but it quickly regenerates from buds.

Reproduction:

Mainly by stems and fragments that root at the nodes. Rarely by seed.

Flowering times:

July to September in SA.
August to October in Perth.
Some flowers present at most times of the year with a flush in winter and spring in WA.
Mainly May to December in SE Australia.
Spring to Summer in NSW.

Seed Biology and Germination:

Seed rarely viable in Australia. Seedlings have been seen in bushland situations in the USA.
The species is probably a polyploid descendant of Vinca minor, and this genetic multiplication is usually cited as being the reason for its low fertility.

Vegetative Propagules:

Stems and stem fragments that root at the nodes.

Hybrids:

Cultivar “Variegata” has cream leaf margins and has also naturalised in Australia and New Zealand.
The variegated form often reverts to the green form as it naturalises.

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed of minor importance.
Stems take root at the nodes increasing the size of patches. Stem fragments take root when they are moved by cultivation, disposed of in garden refuse or moved by earthworks or water flows.

Origin and History:

Mediterranean.

Distribution:

NSW, SA, TAS, VIC, WA.
Covers large areas on the Snowy and Tambo Rivers.
New Zealand, United Kingdom, South Africa, USA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Prefers moist and shady areas but will tolerate full sun.

Climate:

Temperate. Mediterranean.

Soil:

Sandy soils. Tolerates most soil types.

Plant Associations:

Dry coastal vegetation, heathland, heathy woodland, lowland grassland, grassy woodland, dry sclerophyll forest, dry sclerophyll woodland, damp sclerophyll forest, riparian vegetation, warm temperate rainforest.

Significance:

Beneficial:

Ornamental.
Used in herbal medicine and as an aphrodisiac.
Commercial preparations were once made from it because it contains alkaloids that were thought to cure diabetes.

Detrimental:

Weed of water ways, pastures, rubbish dumps, stone heaps, homesteads, gardens, streams, flood plains, bushland, cemeteries, moist shady areas, roadsides and disturbed areas.
Single clones can form dense intertwined mats and cover large areas of woodland crowding out pasture, understorey species and preventing regeneration of overstorey species.
Environmental weed of the USA.

Toxicity:

Toxic to horses, cattle and sheep. Contains alkaloids. Poisoning usually occurs when stock have sudden access to clumps.

Symptoms:

Horses, diarrhoea.
Cattle, rapid breathing, apparent blindness, frothing at the mouth.
Sheep, sudden death.

Treatment:

Remove stock from infestations.
Restrict water intake.
Drench sheep with 50g of activated charcoal in 200 mL water. Give cattle and horse 5-10 times this dose.

Legislation:

None.

Management and Control:

Small areas can be controlled by digging the plant up and ensuring all the stem fragments are collected and burnt to prevent them taking root.
Larger areas can be mechanically raked to raise the runners off the ground then mown.
It recovers from low intensity fires but high intensity fires will kill it.

Thresholds:

Eradication strategies:

This is difficult to control by hand weeding because stem fragments readily take root or break off. Disposal of stems from hand weeding often leads to new infestations where they are dropped in transport.
Best control has been achieved by spraying the weed until runoff with 50 g metribuzin(750g/kg) plus 25 mL Pulse® in 10 L water in spring (or 2.5 kg/ha metribuzin(750g/kg) plus 0.25% Pulse® for broadacre spraying). This herbicide is slow acting and it may take many months before the weed yellows and dies. Repeat in autumn and spring until the infestation has been reduced to a level where the last remnants can be removed by hand.
In open areas mow or cut the vines (after raking to lift the vines off the ground) in early to late spring and spray the regrowth with the above mixes.
Several applications about 6 months apart are usually required.
Control normally takes 2-3 years.
Glyphosate and metsulfuron are not very effective. Metribuzin has given much better long term control than the hormone herbicides like dicamba, Tordon, and Grazon.
Solarisation by laying sheets of clear plastic over small infestations for 4-6 months is sometimes used but regrowth usually requires herbicide treatment.
Hot fires provide some control.

Herbicide resistance:

None reported.

Biological Control:

Related plants:

Lesser Periwinkle (Vinca minor) has smaller flowers about 2.5 cm diameter and leaves that are tapered at both ends rather than rounded at the base.
White Periwinkle (Vinca alba)
It is in the same family as the toxic Oleander (Nerium)

Plants of similar appearance:

Madeira Vine (Anredera cordifolia)
Morning Glory (Ipomoea indica).
Wandering Jew (Tradescantia fluminensis)

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P78. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P696. Diagram.

Blood, K. (2001). Environmental weeds: a field guide for SE Australia. (CH Jerram & Associates, Australia). P124-125. Photos.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P88.

Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P153.

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P84-85. Photo.

Harden, Gwen J. (1991). Flora of NSW. (Royal Botanic Gardens, Sydney). Volume 3. P518. Diagram.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #1270.1.

Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P524.

McBarron, E.J. (1983). Poisonous plants. (Inkata Press, Melbourne). P32. Diagrams.

Moore, J.H. and Wheeler, J.R. (2002). Southern Weeds and their Control. Photos.

Muyt, A. (2001). Bush Invaders of South-East Australia: a guide to the identification and control of environmental weeds found in South East Australia. (R.G and F.J. Richardson, Australia). P153-154. Photos.

Randall, J.M. and Marinelli, J. (1996) Invasive Plants. (Brooklyn Botanic Gardens Inc. Brooklyn) P83.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.