Silky wattle
When many other plants are not flowering, the silky wattle (Acacia holosericea) provides lovely colour in the garden over winter with its spikes of bright yellow flowers from June to August. The botanical name is derived from the Greek ‘holos’ (whole) and ‘sericos’ (silky) that describe the velvety texture, due to fine hairs, of many parts of the plant. This densely-crowned shrub is ideal for home gardens as it is fast growing to about 3m and can be trimmed into a hedge or feature plant. Although the plant is worth growing for its flowers, the masses of twisted seed pods provide a pleasing display. The silky wattle produces leaves as a seedling but, like most members of this group, the mature plant forms phyllodes. These are flattened, leaf-like stems that are an adaptation to help conserve water. The phyllodes of this species are relatively large and with their three to four prominent, parallel veins are another
Acacia holosericea. Photograph by Heather Knowles.attraction.
As with all members of Acacias, the silky wattle has root nodules that harbour nitrogen-fixing bacteria. This allows them to produce their own nitrates, essential for protein formation, and so grow in very nutrient-poor soils. These nitrates are then available for other plants. As a consequence, it is a natural pioneer species that can be used for restoring native woodland, establishing woodland gardens, for revegetation and restoration of degraded sites.
The silky wattle has long been used by indigenous people. The seeds, when cooked, are nutritionally significant with a high protein and carbohydrate content and a low glycaemic index which ensures prolonged exercise. The dry seed was ground to a coarse flour for a variety of uses. The bark, which contains tannins and is astringent, was soaked in water. Taken internally this was used to treat diarrhoea, dysentery and internal bleeding whilst applied externally it was used to treat skin conditions and wounds. A red dye was obtained from the lipid-rich arils, a fleshy accessory seed coat, by soaking them in water. The plant was used as a fish poison. The dried seed pods are sticky and when rubbed remove dirt from the skin (thus the plant’s alternative name, soap bush). The hard, high-density wood was used to make spear shafts. This same characteristic makes the timber useful for wood-turning and in charcoal production.
