Acacia cognata (river wattle)

Japanese name: アカシア コグナタ
Scientific name: Acacia cognata

[Overview]
An evergreen shrub or tree; large specimens reach about 10 m in both height and spread.
The branches arch or hang down, and on the twigs low green to brown ridges alternate with bands of sticky resin.
The leaves are alternate, slightly curved phyllodes, linear to narrowly oblong, 4–10 cm long and 1–3.5 mm wide, sparsely hairy or hairless, with 3 veins and pointed tips.
The leaf margins are entire and have marginal hairs.
One or two globular flower heads grow in each leaf axil, and each head bears 10–25 pale yellow flowers.
The fruit is a slender, flat, papery pod 3–10 cm long and 2–4 mm wide, slightly constricted between the seeds.

[Cultivation]
Propagate from seed.
To promote germination, soak the harvested seeds in 80°C water for 30 minutes, leave them in the water for half a day to 2 days, and then sow.
The optimum germination temperature is 20–25°C, and germination begins about 1–3 weeks after sowing.
It prefers a sunny, well-drained, well-ventilated place.
In warm regions from the Kanto region southward, it can overwinter in the open ground.
It will not flower without enough sun.
It tolerates light frost.
Once established, plants need no watering unless the soil becomes extremely dry.
In summer, water in the morning or evening when the temperature is low.
Pruning hard after flowering can prolong the life of the tree.
Mature trees are difficult to transplant, but if it is unavoidable, root-prune them the previous year.
Pests and diseases include scale insects and aphids.

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