Vinca

Vinca

Vinca
Genus:	Vinca
Family:	Apocynaceae
Type:	Perennials
Pollination:	Insects
Toxicity and edibility:	Toxic if eaten.

Vinca is a genus of five species of in the family Apocynaceae, native to Europe, northwest Africa and southwest Asia. The common name, shared with the related genus Catharanthus, is Periwinkle.

Description

They are trailing vines, subshrubs or herbaceous, and have slender trailing stems 1-2 m long but not growing more than 20-70 cm 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 long and 0.5-6 cm 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 year, are salverform (like those of Phlox), simple, 2.5-7 cm broad, with five usually violet (occasionally white) petals joined together at the base to form a tube. The fruit consists of a group of divergent follicles; a dry fruit which is dehiscent along one rupture site in order to release seeds.

Species

The two most commonly grown species are Vinca major and Vinca minor

Uses

Two species, the Small Periwinkle V. minor and the Large Periwinkle V. major, are very popular ornamental plants in gardens, grown for dense evergreen ground cover and their delicate violet flowers. V. major has broader leaves with a hairy margin and larger flowers, is less cold hardy, and has twice as many chromosomes as V. minor. A variegated selection of V. major is commonly cultivated. Both species are considered invasive weeds in parts of the United States and Australia. They do not respond to common herbicides and require hormone based sprays to control.

This plant was formerly used in homeopathy for catarrh and dyspepsia but due to the nature and effects of the alkaloids vincamine, isovincamine and vincamidine, it is rarely used. The chemotherapy drugs vincristine and vinblastine are derived from this plant.

Maintenance

Remove any leaf cover in the fall to prevent fungal problems.

Propagation

Propagated by cuttings.

Pests and diseases

Blight

• Botrytis cinerea

Canker, Dieback

• Phoma exigua var. exigua (asexual stage Diaporthe vincae)

Leaf Spots

• Alternaria
• Colletotrichum
• Macrophoma vincae
• Phyllosticta
• Phyllosticta minor
• Phyllosticta vincae-majoris

Root Rot

• Pellicularia filamentosa

Nematodes

• Meliodgyne haple
• Xiphinema americanum

Aphids

• Green Peach Aphid: Myzus persicae
• Oleander Aphid: Aphis nerii
• Crescent-marked Lily Aphid: Neomyzus circumflexus

Scales

• Brown Soft Scale: Coccus hesperidum

Hoppers

• Aster Leafhopper: Macrosteles facifrons

Whiteflies

• Silverleaf Whitefly: Bemisia argentifolii

Mealybugs

• Citrus Mealybug: Planococcus citri

Earwigs

• European Earwig: Forficula auricularia

Thrips

• Flower thrips: Frankliniella thricti

Gallery

• 
  Large Periwinkle (Vinca major) flower
• 
  Vinca minor (above), Vinca major (below); leaves for comparison
• 
  Vinca minor (above), Vinca major (below); leaf margins for comparison; note hairless margin of V. minor, hairy margin of V. major

References

• Flora Europaea: Vinca
• Virtual Flowers Vinca
• Blamey, M., & Grey-Wilson, C. (1989). Flora of Britain and Northern Europe. Hodder & Stoughton.
• Huxley, A., ed. (1992). New RHS Dictionary of Gardening 4: 664-665. Macmillan.
• Pirone, Pascal P. (1978). Diseases & Pests of Ornamental Plants (Fifth Edition ed.). John Wiley & Sons, New York. pp. 530–531. {{cite book}}: |edition= has extra text (help); Cite has empty unknown parameter: |coauthors= (help)
• Cranshaw, Whitney (2004). Garden Insects of North America: The Ultimate Guide to Backyard Bugs. Princeton University Press. p. 625. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)