Ivy
Ivy ( Hedera helix)
Ivy ( Hedera ) is a genus of flowering plants in the family Araliaceae ( Araliaceae ). The in Central Europe far the best known species is the Common Ivy ( Hedera helix).
Description
The ivy species are evergreen climbing plants or ground cover. The change-constant and stalked leaves have quite differently shaped leaf blades. Stipules are present or absent.
The racemose inflorescences are composed of doldigen partial inflorescences. The flowers are radial symmetry fünfzählig. It is a discus available. It's just a circle with five fertile stamens present. The five carpels are fused to an inferior ovary. Are formed spherical fruits. The seeds are ovate.
Particularly striking in all kinds Ivy is the Heterophyllie: shape ( and size) of the leaves and also the habitus are different for youth and age forms. The different leaf and growth forms are retained during vegetative propagation by cuttings. This resulted especially in Hedera helix about 400 varieties, which differ especially in leaf colors and shapes.
All plant parts are poisonous due to their saponin ( esp. Hederin ). Ingestion of large amounts of lead in children to crushing diarrhea and cramps. Poisoning resulting in death are known. However, inclusion of the necessary quantity of plants occurs only very rarely due to the bitter taste of the fruit also hard.
Occurrence
The Hedera species are originally distributed by the Macaronesian islands over Europe and the Mediterranean to temperate Asia. Naturalizations are available in New Zealand and the Juan Fernández Islands.
Systematics and species
The genus Hedera in 1753, first published by Carl Linnaeus in Species Plantarum, Volume 1, page 202. Synonyms for Eleutherococcus are Psedera Neck. and Helix Mitch.
There are seven to ten (up to 15) ivy species ( Hedera ), where by far the most widely used in Europe Type of Common Ivy ( Hedera helix) is. Here is a list of types:
- Hedera algeriensis Hibberd, from northwestern Africa.
- Hedera azorica Carrière, in the Azores.
- Hedera canariensis Willd., In the Canary Islands.
- Hedera colchica (K. Koch) K. Koch, with a spread between the Black Sea and the Caspian Sea, and from the Caucasus, Syria and Cyprus.
- Hedera helix L. ( Common Ivy or common ivy ), with wide distribution in Europe.
- Hedera hibernica (G. Kirchn. ) Carrière, on the Atlantic coast.
- Hedera maderensis K. Koch ex A. Rutherf. , On Madeira.
- Hedera nepalensis K. Koch, from the entire Himalayan region at altitudes up to 2300 meters, China and Taiwan.
- Hedera pastuchovii Voronov, in very small areas in the West Caucasus and Iran, this species is known only since about 1930.
- Hedera rhombea ( Miquel ) Bean, from Japan to the Ryukyu Islands, Korea and Taiwan.
The distribution of Hedera canariensis in four species: H. canariensis, H. algeriensis, H. and H. azorica maderensis is controversial.