Gerald McCormack, CINHT
Leaves, flowers and fruit (1) – Cook Islands, Rarotonga – Gerald McCormack
The Toa (Ironwood) of the Cook Islands, Casuarina equisetifolia, is a native tree of Malaysia, Australia and some islands in the western Pacific. It was probably spread eastward through Southern Polynesia by the ancient Polynesian settlers, and now grows naturally on many islands.
Throughout the Southern Group it grew well and spread naturally along the shorelines and into the fernlands of the inland mountains. In contrast, it did not grow well nor spread itself on the northern atolls, where it is uncommon, rare or absent.
The thin green parts which look like leaves are not leaves; they are green branchlets, which perform the leaf-function of changing the energy of sunlight into the energy of sugars. When you snap a branchlet, the minute pale projections at the break are all that remain of the true leaves.
Leaves, flowers and fruit (2) – Cook Islands, Mangaia – Gerald McCormack
Although the Toa looks like a relative of the pine tree, it is more closely related to the hibiscus and gardenia than the pine. The Toa is a flowering plant. The female flowers are each represented by a delicate pink filament on a small knob on the branch among the green branchlets. When they have been pollinated the knob grows into a woody fruit which contains lots of small seeds. The pollen is made by the male flowers which are the pale, bushy tails, typically on the ends of some branchlets.
Toa in general, and sometimes the heartwood (taiki), is the preferred wood for making many things, such as: beaters (tïtï) for slit-gongs; outrigger booms (kiato) on canoes; planting sticks for Taro (pao-taro); adze-handles (kakau-toki); recreational throwing discs (pua); and, parts of the framing of traditional dwellings. In pre-Missionary times it was also used to make spears (räkau), clubs (patu) and God-images (atua).
A solution made from scrapings of the inner bark is one of several herbal medicines (vai räkau) used for mouth thrush (kea) in children and for some urinary problems (mimi and mimi-tätua).
The English name Ironwood is used in different countries for different species of trees and is therefore confusing to overseas visitors. In Australia Casuarina equisetifolia is known as Beefwood, Horsetail Tree or Sheoke. The name Sheoke is thought to be a combination of ‘sshh’ (the sound of the wind passing through the branchlets) and ‘oak’ (the wood being very hard, like European Oak).
First published CINEWS (18 June 1994)
