PlantFiles: Austral Grass-tree
Xanthorrhoea australis

Austral Grass-tree is one of several Australian plants of unusual form. They have long grass-like leaves, but most species grow a hard woody trunk, eventually growing to a height of over two metres, with the tuft of grass-like leaves at the top. When they flower, they put up a tall spike of flowers, which may add an additional 2 to 3 metres to the plant. The flowers are strongly scented, smelling of honey and are very attractive to bees and birds (Australian honeyeaters). They are very slow growing and some are said to be over 200 years old. They are a protected species, but mature plants are offered for sale (at a high cost). These are collected under licence usually when land containing grass-trees is being cleared. They grow fairly readily from seed, but you need a great deal of patrience to get a plant that looks like a grass-tree and to ever see a flower spike.
Flowering is spasmodic. In an area with many grass-trees, one will usually see only a scattering of plants in flower, but if a bushfire occurs in the area, the next year there will be a spectacular flowering of the grass-trees. Flowering is more likely if the plant is in full sunlight.
I have grown plants from seed for establishing in our local park, and I have a small plant established in my garden, but many years away from its first flowering.