Black Sheoaks grow between 2 and 10 m tall.
They are often said to have leaves of ‘pine needles’, but these are shoots or ‘cladodes’. Minute leaves are arranged in whorls around each joint. Each point on the whorl is a leaf.
This is an adaptation that enables the Sheoak to minimize the water it needs and also the moisture lost through its leaves. A very important adaption in Australia’s often arid and variable climate.
The Sheoak is able to ‘fix’ nitrogen in the soil through symbiotic bacteria that live in nodes on their roots. As Australia's soils are often poor this natural fertiliser is critical for other species.
Photo R Miller
The shoots and leaves fall to the ground and form dense mats of “pine needles” under the tree.
This mulch keeps the soil moist and helps the tree survive dry periods. The mulch prevents other plants from growing underneath them and limits competition for the available nutrients and water.