Yakkas (Xanthorrhoea semiplana and X. quadrangulata)

This old man is in the Flinder’s Ranges and is reputed to be over 100 years old

Family: Asphodelaceae

Habitat: Forests, heaths

Flowering Times: X. semiplana – Spring. X. quadrangulata – Autumn to Spring.

Ngarrindjeri name: Bukkup

Kaurna name: Yakko or Kurru

Description and uses:

Yakkas (Xanthorrhoea sp) or ‘Grass Trees’ are common around Gawler and most of South Australia. They consist of a thickened stem, long, sharp, pointed leaves and a distinctive flower spike. Yakkas thrive where there are bushfires. The leaves only get burnt so far down, leaving the interior and leaf bases untouched, well insulated against the fire’s heat.

The leaves are quite hazardous to one’s health. The edges are sharp as knives, it feels like a bad paper cut when they get you. The ends are sharply pointed and have that ‘invisible’ quality when you’re working with them. You think you’re clear then ‘ouch’ right in the eye!

While on the subject of leaves, there are two varieties of Yakka down this way and the easiest way to tell them apart is by looking at their leaves. Their species name describes the leaves when cut across, in cross section. X. semiplana has flat leaves while X. quadrangulata are a slightly squashed square shape with four distinct corners.

X. semiplana in cross section
X. semiplana in cross section. It’s almost flat…or ‘semi planar’

X. semiplana is more common around this way, while X. quadrangualta is more commonly found toward the Flinder’s Ranges.

The flower spike is quite spectacular, often reaching a couple of metres in length. It is bare at its base and for a short way up, then you find the flowers. There are many tiny, 3 petaled cream coloured flowers. Even though it isn’t necessary, fire will often trigger the flowering of Yakkas.

The wood of the spike is very light and usually pretty straight, making it most suitable for making light spears. The base of the stalk is commonly used for making fires with the drill method.

Yakkas thrive in a variety of conditions

One use of the flower stalk is to make a sweet drink by soaking it in water for a while. Sometimes, the flowers are so loaded with nectar that folks have been seen licking them straight off the spike (it’s actually quite good)!

The flower spike is full of hundreds of little flowers

The resin found in burnt trunks is an indispensable adhesive for the Indigenous folk who have long used it for fixing the heads to spears or repairing container. It softens with heat and sets rock hard, so is an ideal cement. Unlike some Wattle gums, it’s not good to eat.

The roots are also quite tasty. I prefer them raw to cooked as they can be deliciously juicy.

Yakka resin is used as a strong glue

Wikipedia has some interesting European uses in its entry for Xanthorroea

  • Burnt as an incense in churches.
  • A base component for a varnish used on furniture and in dwellings.
  • A polish and a coating used on metal surfaces including stoves, tin cans used for storing meat and “brass instruments.”
  • A component used in industrial processes associated with “sizing paper, in soap making, perfumery and in manufacturing early gramophone records.”

Yakkas, interesting and spiky!