Black wattle
Acacia mearnsii
Family · Fabaceae · Harmless
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The country's third invasive wattle, the one with twice-divided dark green leaves, dominating streams and banks in Madeira and the mainland north.
Roadsides and waste ground · Streams and ditches · Oak woods · Scrubland
Also known astan wattle, late black wattle
How to tell it
A tree five to fifteen metres. True leaves, twice divided into many minute leaflets, dark green and not silvery, which separates it from silver wattle. Between each pair of leaf branches there is a visible gland, and that is the most reliable mark. Flowers in pale cream balls, later than silver wattle.
What it is confused with
Silver wattle
Acacia dealbata
Both have twice-divided leaves. Silver wattle is silvery and flowers bright yellow in January; this is dark green and flowers cream in May. And this has a gland between every pair of leaf branches, silver wattle only on some. Both are invasive.
Open sheet →What it is for
None to encourage. The bark is extremely rich in tannin and was the reason it was planted: it fed the tanning industry. Today it is a listed invader, fixes nitrogen and alters the soil in ways that favour other exotics and harm natives.
The law says
A listed invasive alien species in Portugal. Do not plant or propagate it.