Japanese name: ギンゴウカン（銀合歓） Scientific name:Leucaena leucocephala
[Overview]
An evergreen shrub to tree about 4–8 m tall.
Some reach 10 m in height.
The leaves are alternate and bipinnately compound with an even number of leaflets, bearing 6–8 pairs of pinnae 6–10 cm long.
The leaf axis, including the petiole, is 12–20 cm long and has soft hairs.
Each pinna bears 14–16 pairs of long-ovate leaflets about 8–13 mm long and 2–3 mm wide.
The leaflets at first have white hairs on the margins, but later become hairless; the margins are entire.
It flowers almost all year round.
Flowers are densely packed in globose heads about 2 cm across arising from the leaf axils.
The white stamens of the flowers are conspicuous.
The stalk of the flower head is 3–5 cm long.
The fruit is a flat pod 10–17 cm long and 1.5–2 cm wide, containing 10–25 elliptic seeds.
[History]
Introduced for greening, green manure, erosion control and similar purposes, to the Ogasawara Islands in 1862 and to the Sakishima Islands after 1910, it has become naturalized.
[Notes]
It is designated as an Invasive Alien Species Requiring Caution under the Invasive Alien Species Act.
