Trees

Jarrah (Eucalyptus marginata) and occasionally Tuart (Eucalyptus gomphocephala) or Marri (Corymbia calophylla) form the upper canopy of trees in Warwick Bushland. Tuart tends to grow on the ridges of the dunes and towers over the Jarrah and Banksia trees when mature. In most areas the Candle (Banksia attenuata) and Firewood Banksias (Banksia menziesii) occur on their own or form a second tree layer below the eucalypts. The Bull Banksia (Banksia grandis) and Sheoak (Allocasuarina fraseriana) are less common but scattered throughout the site and there are several Christmas Trees (Nuytsia floribunda). A fourth species, the Acorn Banksia (Banksia prionotes) does not naturally occur in Warwick Bushland but is in nearby reserves (such as Yellagonga Regional Park) and has been extensively planted on the margins of Warwick Bushland. Marri occurs naturally in a few patches of more fertile soil but have also been planted in the bushland.

Large older trees provide an important habitat and food source for native fauna. For example, the tree hollows in mature Eucalypts and Marri provide nesting sites for cockatoos and parrots. These trees can take 100-200 years to develop hollows that are a suitable size for nesting for the large Carnaby’s Black Cockatoo.

Each of the banksia species flowers in a different season, providing an almost continuous source of nectar and pollen for the birds and insects throughout the year. Banksia flowers and fruit also provide important food sources for birds, such as Carnaby’s Black Cockatoos (see Birds).

Tuart Tree with flowers
Eucalyptus gomphocephala

Tuart Tree Flowers
Eucalyptus gomphocephala

Marri Tree with Gumnuts
Corymbia calophylla

Menzies Banksia with Developing Seed
Banksia menziesii immature cone

Menzies Banksia – A winter flowering tree
Banksia menziesii

Acorn Banksia flowers up close
Banksia prionoites

Sheoak Branches Sprouting after Fire
Allocasuarina fraseriana

Female Sheoak with Seed Cones
Allocasuarina fruit

Sheoak Tree Resprouting after Fire
Allocasuarina fraseriana

Male Flowers on Sheoak
Allocasuarina fraseriana

Jarrah (Eucalyptus marginata)

Jarrah trees have stringy grey bark that protects the reddish coloured trunk from fire. White flowers are produced from spring to early summer, followed by globular cup-shaped nuts. Jarrah trees can grow up to 40 metres high with a trunk up to 3 metres in diameter. The biggest and best quality trees were removed by logging many decades ago but their stumps can still be seen, some trees even re-sprout from these stumps.

Many hundreds of insect species can be found on just one Jarrah tree alone. Other tree species such as Tuart and Marri support similar native invertebrate fauna.

Candle Banksia (Banksia attenuata)

The Candle Banksia is one of the most common banksias found across much of the Southwest of Western Australia. It is also referred to as the Slender Banksia due to its slender leaves. The leaves of the Candle Banksia have distinctive serrated edges, and are covered in spectacular – looking hairs as they grow, as shown here. During spring and summer (October to February) these trees produce numerous large yellow flower spikes up to 25cm tall and 5cm wide that look like candles.

The middle image shows a fallen banksia cone that was probably dropped by a Carnabys’ Black Cockatoo, which fed on them in winter. A germinating banksia seed is located next to the cone. Some seeds from banksia cones automatically fall every summer, so if you are observant, you will find banksia seedlings scattered throughout the reserve in winter.

The Candle Banksia flowers provide a great food source for nectar-eating birds, like the Wattlebird below, and insects. There is always a species of Banksia in flower at Warwick Bushland, providing a food source all year around.

Menzies Banksia (Firewood Banksia – Banksia menziesii)

These trees are very common in Warwick Bushland and produce many beautiful flowers in winter that contain abundant nectar. The two coloured red or pink and yellow flowers spikes are produced from February to October, providing nectar and pollen for nectar-feeding insects and birds such as honey eaters. The mature flower cones contain seeds and grubs that are an important food source for the endangered Carnaby’s Black Cockatoo.

Large intricately branched galls are very common on these trees. These are caused by unknown insects that induce cancer-like growths in which they live. These are common so trees must be used to supporting these freeloaders. You will often also see smaller galls inside banksia leaves.

Christmas Tree (Nutysia floribunda)

The bright yellow-orange flowers of this tree are displayed during the Christmas period (upper photo). It can be a shrub or tree growing up to 10 metres high. The flowers provide a rich source of pollen and nectar for birds and insects.

This tree is actually a type of mistletoe, most of which live as epiphytes attached to tree branches. However, this species is a root parasite that gains the majority of its water and nutrients from other plants. The lower photo shows the underground organs Nuytsia uses to do this. These are doughnut-shaped rings that latch onto the roots of other plants (5-15cm wide). These haustoria first sever the attached root and then establish a direct connection to the host’s vascular tissues. It has been reported that these can latch onto the roots of plants up to 150 metres away.

Trees

Jarrah Tree Flowers Opening

Eucalyptus marginata fruit

Tuart Tree with flowers

Tuart Tree Flowers

Marri Tree Flowers

Marri Tree with Gumnuts

Candle Banksia new leaves and flowers

Candle Banksia

Candle Banksia Cone

Firewood Banksia

Menzies Banksia with Developing Seed

Menzies Banksia Flowers

Parasitic Insect Gall on Banksia menziesii

Menzies Banksia – A winter flowering tree

Bull Banksia in Flower

Bull Banksia Flowers

Acorn Banksia Flowers

Acorn Banksia flowers up close

Sheoak Branches Sprouting after Fire

Female Sheoak with Seed Cones

Sheoak Tree Resprouting after Fire

Male Flowers on Sheoak

West Australian Christmas Tree

Friends of Warwick Bushland

Acknowledgment of Country

Supported by City of Joondalup

Warwick Bushland