Anyone who has visited the Fleurieu Peninsula would know that it is synonymous with the Xanthorrehoea Semiplana. Often referred to as grass trees, yacca or in earlier times black boys this plant is truly remarkable. It is an exceptionally slow growing plant and long lived with some specimens estimated to be 450 years old.
In fact, the rough trunk only develops after many years of growth. Its typical black appearance is the result of exposure to bush fires over decades. The reason the plant usually survives a fire is that its living growth-point is buried underground, protected by a tightly packed leaf base.
Growth rates, although hard to quantify, have been estimated at between 1-3 cm per year. Flowering takes several years and does not happen annually. However, after bushfires up to 80% of Xanthorrehoea will flower producing a single spear-like cream coloured stem that can reach up to 3m in height.
Yaccas were an important plant for local Aboriginal communities both as a source of food and drink as well as for fibre and materials for tool and weapon construction. The flowering stem, when soaked in water, produces a sweet drink while it also releases a resin that was used as a glue when making tools. Stems could also be used as part of a spear or as a base for fire making implements and the tough seed pods were used as cutting implements.