Brachylaena discolor is a species of flowering plant in the aster family, Asteraceae. It is native to Africa, where it occurs in Mozambique, South Africa, and Eswatini.[1] Its common names include coast silver oak and coastal silver oak.[2] [3] [4]
This species is a shrub or tree up to about 10 meters tall,[1] but known to reach 27[2] to 29 meters at times.[4] The branches are brown or purple-tinged, and hairy when new. The leaves are oval or oblong and usually up to 12 centimeters long. They are smooth-edged to toothed to spine-toothed. They are mostly hairless and a shiny dull green on top and grayish hairy underneath. Flowers are borne in large panicles at the ends of branches and shorter panicles in the leaf axils.[1] The species is dioecious, with flower heads that look like "plump shaving brushes".[4] Male plants have heads with short phyllaries and a single layer of pappus hairs. Female heads have longer phyllaries and multiple layers of pappus hairs.[1]
The plant grows in coastal forests, on the edges of mangroves, and along rivers.[1]
The flowers produce abundant nectar and attract insects and birds. It is a good honey plant. The leaves may be browsed by antelopes such as nyala, bushbuck, and duikers.[2]
This species has become naturalized in Queensland, and is a potential weed.[3]
The yellow wood is strong and has been used for many purposes, including the construction of boats, fences, housing and roofing, axles, tools, and knobkierries. It is considered a valuable carving wood. The ash was used in the production of soap.[2]
The plant was used medicinally by native Africans and European settlers. It has been used to treat kidney conditions, diabetes, gastrointestinal bleeding, intestinal parasites, and chest pain.[2]
It is also cultivated as an ornamental plant for gardens and landscaping. It tolerates coastal habitats and can be used to stabilize dunes.[2]
Some authors divide the species into two varieties, var. discolor and var. transvaalensis (forest silver oak or Natal silver oak). Others treat var. transvaalensis as Brachylaena transvaalensis, a separate species.[3] [4] Its leaves have a distinctive shape and its flower heads are smaller and different in morphology.[1]