T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Albizia julibrissin (Silktree)

Kingdom:   Plantae
(Unranked):        Angiosperms
(Unranked):        Eudicots
(Unranked):        Rosids
Order:       Fabales
Family:      Fabaceae
Genus:      Albizia
Species:     A. julibrissin
Binomial name: Albizia julibrissin
Common name: Persian Silk Tree, Pink silk tree, Pink siris, Mimosa, Lenkoran acacia, Bastard tamarind

Albizia julibrissin is a species of tree native to southwestern and eastern Asia. It is a small deciduous tree growing to 5–12 m tall, with a broad crown of level or arching branches. The bark is dark greenish grey in colour and striped vertically as it gets older.
The leaves are bipinnate, 20–45 cm long and 12–25 cm broad, divided into 6–12 pairs of pinnae, each with 20–30 pairs of leaflets; the leaflets are oblong, 1–1.5 cm long and 2–4 mm broad. Its leaves slowly close during the night and during periods of rain, the leaflets bowing downward.
The flowers are produced throughout the summer in dense inflorescences, the individual flowers with small calyx and corolla (except the central ones), and a tight cluster of stamens 2–3 cm long, white or pink with a white base, looking like silky threads. These sweet-scented flowers are a good nectar source for honeybees and butterflies.
The fruit is a flat brown pod 10–20 cm long and 2–2.5 cm broad, containing several seeds. These pods are produced in abundance.  They are designed to release a burst of pods with every strong wing, and to carry over surprisingly long distances.  The tree never seems to be without at least a few remnant pods.

Albizia julibrissin has become an invasive species in Japan and the USA because it’s high seed production and almost virulent level of viability.