r.1 - part

5. Acacia mearnsii
Botanical Name Acacia mearnsiiDe Wild.
Synonyms Acacia decurrens (Wendl.) Willd. var. mollis Lindl., A. mollissima
auct., non Willd.
Common Names black wattle (Australia); tan wattle, green wattle, Australian
acacia; wattor-ju (Okinawa); acacia negra (Colombia); mwati (Tanzania).
Legume Family, Leguminosae (Mimosoideae)
The world's main source of tanbark is recognized by its feathery, dark green
foliage with numerous tiny crowded soft hairy leaflets; tiny pale yellow
flowers in balls; narrowly ohlong, flat and rough pods narrowed between
seeds; and the blackish, nearly smooth bark. Acacia mearnsii is native to
southeastern Australia but has been introduced around the world. It is a
fuelwood species for tropical highlands.
Description Small to large evergreen tree 6-25 m high, with straight trunk
to 50 cm in diameter and spreading rounded crown of feathery, dark green
foliage; or when crowded in plantations erect and slender, without spines.
Bark blackish or brown, nearly smooth. Twigs angled, gray, densely hairy,
tinged with golden yellow when young.
Leaves alternate, feathery, bipinnately compound, very soft hairy, 8-15 cm
long, with 6-20 pairs of side axes (pinnae)2-5 cm long and round gland at base
of each pair on upper surface. Leaflets very numerous, 20-70 pairs on each
side axis (pinna), small, crowded and touching, narrowly oblong, 3 mm long,
blunt, with dense soft hairs, yellowish when young, becoming dark green.
Flower clusters (racemes) along axis at leaf base or terminal, composed of
many (20-30) stalked, pale yellow balls (heads) 7-8 mm in diameter. Flowers
many, tiny, very sweet-scented, composed of narrow 5-lobed calyx, corolla of
5 petals, many threadlike, pale yellow stamens, and pistil with long, slender
style.
Pods (legumes) narrowly oblong, 5-10 cm long, 5-9 mm wide, flat, rougb,
narrowed between seeds, blackish, finely hairy, maturing in 14 months. Seeds
several, beanlike, elliptical, flattened, blackish, 4 mm long.
Wood light yellowish to light red, heavy (sp. gr. 0.7-0.85), moderately hard
to hard, durable, fairly tough and strong. Yields excellent fuelwood and charcoal;
serves also as fuel for curing tobacco.
Other Uses Used for poles and mine props. Pulp suitable for wrapping
paper and hardboard. World's main source of tanbark, perhaps containing
35-40 percent tannin of good quality, used in manufacture of hard leathers for
shoes, saddles, etc.
Trees planted for erosion control and shelterbelts on steep slopes and poor
soils, as well as for fuelwood and charcoal. Soil improved fcr agriculture by
nitrogen fixation and green manure. Forests provide grasses and herbs for
grazing. Acacia mearnsiiand related species attractive ornamentals, flowering
profusely in late winter.
ACACIA MEARNSII
15