Three-cornered leek - Invasive Species Information
Three-cornered leek is a bulbous flowering plant in the genus Allium (onions and garlic) native to the Mediterranean basin. This spring-flowering bulb carries 2cm long bell-like white flowers (10-18mm) on stems which are three-sided and about 30cm high. Along the centre of each petal is a narrow green line and between 3 and 15 flowers are arranged in a drooping one-sided umbel not unlike that of a Bluebell.
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The leaves are very markedly angled, coming three to a plant from the base. From April to June these flowers can be seen growing along roadsides, in hedges, banks and other shady places. The leaves have a distinct onion smell when crushed.
Reproduction: The seeds of Three-cornered leek are spread naturally by ants and other insects.
Three-cornered leek flower
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Colour: Mid-green
Flower: White with green line on each petal
Leaf: Green with distinct angle
Stem: 3 sided
Smell: Onion / Garlic
How To Identify Three-cornered leek?
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Three-cornered leek stem
Three-cornered leek - Allium triquetrum ID Guide
Three-cornered leek flowers
Three-cornered leek roots
Why Is Three-cornered leek A Problem?
Threatens biodiversity where the plant forms early season dense monocultural masses, particularly at protected sites.
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Three-cornered leek is known to have serious impacts on the natural habitats that it invades and is very aggressive, having the potential to rapidly occupy large tracts of land.
Plants forms dense and persistent stands that totally dominate the ground-flora when conditions are suitable (moist and shaded). These stands crowd out and displace the indigenous grasses and groundcovers and can also seriously impede the regeneration of the over-storey vegetation.
What Is Three-cornered leek - (Allium triquetrum)?
Habitat: Terrestrial. Prefers damp shaded areas
Distribution in Ireland: Widely distributed in the south and south east
Status: Established
Family name: Amaryllidaceae
Common name/s: Three-cornered garlic
European Communities (Birds and Natural Habitats) Regulations 2011 non-native invasive plant species A-Z (Updated 2017)
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There are currently 35 invasive plant species listed in the European Communities (Birds and Natural Habitats) Regulations (annex 2, Part 1)...
Click on a species from the following list to find out more regarding non-native species subject to restrictions under Regulations 49 and 50.
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American Skunk-Cabbage - Lysichiton americanus
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Red Alga - Grateloupia doryphora
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Waterweeds - Elodea (all species)