This member of the Araliaceae family was described by Carl Peter Thunberg in 1780. It is found in southern South Africa, growing in a well drained soil with some water and some sun. It will grow to five meters in height, and the caudex can grow to 60 centimetres in diameter. The flowers are stellate, greenish and bi- or unisexual. The genera is named after Pierre Cusson, 1727-1783, a French physician, botanist and mathematician. The species means 'thyrse-flowered'.

