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Butterfly-bush

Invasive Species Information

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What Is Butterfly-bush - Buddleja davidii?

Habitat: Terrestrial
Distribution in Ireland: Locally abundant in some places

Status: Established

Family name: Buddlejaceae

Reproduction: The honey-scented lilac to purple inflorescences are terminal panicles, < 20 cm long. Flowers are perfect (having both male and female parts), hence are hermaphrodite rather than monoecious (separate male and female flowers on the same plant) as is often incorrectly stated. Numerous seeds are produced and distributed by wind and water.

Butterfly-bush - Buddleja davidii Flower

Butterfly-bush Flower

Butterfly-bush - Buddleja davidii Leaves

Butterfly-bush leaves

The Butterfy-bush is a perennial shrub is able to grow just about anywhere; waste ground, embankments, even on the rooftops derelict buildings and, It is a shrub which branches from ground level. 

 

From May to August it carries long, conical 4 lobbed pink, mauve. lilac, yellow or white flowers (3-4mm across) which have a small orange 'eye' which are strongly scented. 

Butterfly-bushes are vigorous shrubs with an arching habit, growing to 5 m in height. The pale brown bark becomes deeply fissured with age.

 

The branches are quadrangular in section, the younger shoots covered in a dense indumentum.

 

The plant has lanceolate, opposite leaves (7–13 cm long) which are grey-green and has arching stems which are light coloured, appearing somewhat cracked. Butterfly-bushes are upright, multi-stemmed shrubs. In northern climates it will typically be killed back to the ground frosts.

How To Identify Butterfly-bush?

Butterfly Bush - Buddleja davidii - ID Guide

Leaf: Opposite, simple, ovate to lance shaped, finely serrated, 7-13 cm long, dark green above, white-fuzzy underlay.
Flower: Narrow, upright spikes of deep purple, pink, yellow or white, small individual flowers with four petals.
Fruit: Dry, two-valved capsules, ripen in late summer and autumn.
Stem/Twig: Moderately stout, very angled, initially green, turning light brown, large white pith, small buds.
Bark: Thin, brown, splitting and peeling.

Butterfly-bush - Buddleja davidii ID Guide

Why Is Butterfly-bush A Problem?

Butterfly bush is an invasive plant, meaning it out-competes and crowds out beneficial native plants that have been naturally growing for centuries.

 

In Ireland, butterfly bush, which has origins in Asia, readily spreads and takes over space where native plants would normally thrive. In fact, butterfly bush has life history traits that make it invasive in most environments.

Butterfly-bush - Buddleja davidii Stem

Butterfly-bush Stem

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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  1. American Skunk-Cabbage - Lysichiton americanus

  2. Brazilian Giant-Rhubarb - Gunnera manicata

  3. Broad-Leaved Rush - Juncus planifolius

  4. Cape Pondweed - Aponogeton distachyos

  5. Cord-Grasses - Spartina (all species and hybrids)

  6. Curly Waterweed - Lagarosiphon major

  7. Dwarf Eel-Grass - Zostera japonica

  8. Fanwort - Cabomba caroliniana

  9. Floating Pennywort - Hydrocotyle ranunculoides

  10. Fringed Water-Lily - Nymphoides peltata

  11. Giant Hogweed - Heracleum mantegazzianum

  12. Giant Knotweed - Fallopia sachalinensis

  13. Giant-Rhubarb - Gunnera tinctoria

  14. Giant Salvinia - Salvinia molesta

  15. Himalayan Balsam - Impatiens glandulifera

  16. Himalayan Knotweed - Persicaria wallichii

  17. Hottentot-Fig - Carpobrotus edulis

  18. Japanese Knotweed - Fallopia japonica

  19. Large-Flowered Waterweed - Egeria densa

  20. Mile-a-Minute Weed - Persicaria perfoliata

  21. New Zealand Pigmyweed - Crassula helmsii

  22. Parrots Feather - Myriophyllum aquaticum

  23. Red Alga - Grateloupia doryphora

  24. Rhododendron - Rhododendron ponticum

  25. Salmonberry - Rubus spectabilis

  26. Sea-Buckthorn - Hippophae rhamnoides

  27. Spanish Bluebell - Hyacinthoides hispanica

  28. Three-Cornered Leek - Allium triquetrum

  29. Wakame - Undaria pinnatifida

  30. Water Chestnut - Trapa natans

  31. Water Fern - Azolla filiculoides

  32. Water Lettuce - Pistia stratiotes

  33. Water-Primrose - Ludwigia (all species)

  34. Waterweeds - Elodea (all species)

  35. Wireweed - Sargassum muticum

Additional Non-Native Plant Species identified as Medium Risk on Ireland's Biodiversity List...

Common name 

African woodsorrel

American skunk cabbage

Annual bur-sage

Antithamnionella ternifolia

Barberry

Black currant

Brazilian waterweed

Butterfly-bush

Canadian-fleabane

Clover broomrape

Creeping Bellflower

Dead man's fingers

Douglas fir

Early goldenrod

False acacia

Field penny-cress

Garden lupin

Giant rhubarb

Hairy rocket

Himalayan honeysuckle

Himalayan knotweed

Holm oak

Japanese barberry

Japanese honeysuckle

Japanese rose

Leafy spurge

Least duckweed

Narrow-leaved ragwort

New Zealand bur

Ostrich fern

Pampas grass

Pitcherplant

Red oak

Red sheath tunicate

Rock cotoneaster

Rum cherry

Russian-vine

Salmonberry

Sea-buckthorn

Sycamore

Three-cornered garlic

Traveler's-joy

Tree of heaven

Turkey oak

Virginia-creeper

Warty cabbage

Water fern

Wild parsnip

Species name 

Oxalis pes-caprae

Lysichiton americanus

Ambrosia artemisiifolia

Antithamnionella ternifolia

Berberis vulgaris

Ribes nigrum

Egeria densa

Buddleja davidii

Conyza canadensis

Orobanche minor

Campanula rapunculoides

Codium fragile ssp. tomentosoides

Pseudotsuga menziesii

Solidago gigantea

Robinia pseudoacacia

Thlaspi arvense

Lupinus polyphyllus

Gunnera manicata

Erucastrum gallicum

Leycesteria formosa

Persicaria wallichii

Quercus ilex

Berberis thunbergii

Lonicera japonica

Rosa rugosa

Euphorbia esula

Lemna minuta

Senecio inaequidens

Acaena ovalifolia

Matteuccia struthiopteris

Cortaderia selloana

Sarracenia purpurea

Quercus rubra

Botrylloides violaceus

Cotoneaster horizontalis

Prunus serotina

Fallopia baldschuanica

Rubus spectabilis

Hippophae rhamnoides

Acer pseudoplatanus

Allium triquetrum

Clematis vitalba

Ailanthus altissima

Quercus cerris

Parthenocissus quinquefolia

Bunias orientalis

Azolla filiculoides

Pastinaca sativa

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