Botanic Gardens Trust, Sydney, Australia

Plant info




Appearance

In the wild the trees grow to about 40 metres and their trunks can grow up to 1 metre in diameter.

Like other conifers, it bears cones (male and female - see sex life), which appear at the very tip of branches with adult phase leaves.

The bark is particularly unusual, looking very much like ‘chocolate crackles’ or bubbling chocolate, making it quite different from the bark of other related species.

Leaves

The Wollemi has two types (or phases) of leaves. It does not have needles like pine trees in the northern hemisphere. Its young broad-based juvenile leaves are bright lime-green and grow in low light under the rainforest canopy. The adult leaves, which grow in much harsher conditions above the canopy, are tougher and a deeper bluish-green.

The leaves at the beginning and end of a growing season are shorter than those formed during the middle of the season, creating a diamond shaped pattern along the branch. The leaves also have an in-built system to help reduce water loss.

Branches

There are two types of branches on the Wollemi Pine:
1 - one grows upright (orthotropic), forming a stem or another trunk, depending where it starts
2 - the other grows sideways (plagotropic) from an upright branch and the leaves develop on these branches. Unlike trees in the genus Araucaria, the sideways branches do not divide unless the growing tip (apical meristem) is damaged.

Upright branches start from buds borne along the trunk, eventually maturing with foliage and a branching structure resembling the initial trunk, so that older trees develop a branched crown. Upright branches that develop from buds at the base of the trunk, referred to as coppicing, form a multi-trunked tree.

Young seedlings, from as early as one year old, can develop more than one upright branch - unlike Araucaria trees where additional upright branches develop only after the growing tip has been damaged or wounded.

 

Female (seed) cone and adult leaves
Female (seed) cone attached to a sideways (plagotropic) branch with adult leaves.

Male (pollen) cone and juvenile leaves
Male (pollen) cone attached to a sideways (plagotropic) branch with juvenile leaves.

Wollemi Pine bark
Bark of Wollemi Pine.

Upright (orthotropic) branches from buds on trunk.
Upright (orthotropic) branches developing from buds along the trunk lead to the branched crown of the Wollemi Pine

.Multi-trunked tree formed by self-coppicing
Upright (orthotropic) branches developing from the base of tree (self-coppicing) form a multi-trunked Wollemi Pine.