Blackwood
Acacia melanoxylon
Family · Fabaceae · Harmless
The largest woody invader in Portugal and on the islands too, and it was missing from this guide. It is known by the leaf that is not a leaf: what looks like a long curved leaf is a flattened leaf stalk.
Oak woods · Pine woods · Roadsides and waste ground · Streams and ditches
Also known asAustralian blackwood, black wattle
How to tell it
A tree to thirty metres, with dark fissured bark. What look like leaves are phyllodes: flattened stalks, curved like a sickle, with three to five parallel lengthwise veins and no midrib. Young plants still show true leaves divided into pairs of fine leaflets. Flowers in pale cream balls. Twisted pods with black seeds ringed by a bright red thread.
What it is confused with
Silver wattle
Acacia dealbata
Silver wattle has true leaves twice divided into very fine silvery segments and bright yellow flowers in winter; blackwood has entire sickle-shaped phyllodes and pale cream flowers. Both are invasive and neither is eaten.
Open sheet →What it is for
The timber is excellent and much valued in joinery, which is exactly why it was planted everywhere. Nothing is eaten. It is the hardest invader to control in Portugal because it suckers from the roots after cutting and the seed bank survives decades in the soil, waiting for a fire.
The law says
A listed invasive alien species in Portugal. Do not plant or propagate it.