This forest tree, limited in its natural distribution mainly to the Monterey Peninsula in California, was discovered in the botanical sense by two botanists separately, but at about the same time. Coulter first found it in 1830 and this collection was named Pinus radiata. Very soon afterwards Douglas, a Scottish botanist, collected it and named it P. insignis. It has sometimes been thought that the two names refer to different trees, but this is not so. Radiata pine was, of course, known before it was collected botanically, and, indeed, in Don's description he refers to the timber from the tree as a good shipbuilding timber used by the Spaniards in California. In its native habitat it is a tree which, on the best sites, grows to heights of 150 ft or more and shows great variation in form of growth. It hybridises naturally with at least one neighbouring pine, P. attenuata, and has one or two distinct varieties in islands off the Californian coast.
No other coniferous forest tree has attracted so much attention or shown such great promise of becoming, in the course of time, one of the main forest trees of the world. In all probability close to 1 million acres have been planted, mainly during the past few decades. New Zealand has the largest area, amounting to over 600,000 acres.
The tree seems to have been introduced into New Zealand soon after it was collected from California. It was probably grown in pots and sent out with settlers from England by the forerunner of the Royal Horticultural Society. Its rapid growth, prolific seed production, and ease of handling as a seedling soon made it a favourite tree for shelter planting. As time went on, trees from these shelter belts were used for timber which proved to be of good general utility. This fact, together with the tree's fast growth and ease of handling as a forest tree, led to wide-scale planting in the years 1925–35. Although the rate of planting decreased after that date, radiata pine had by then become established as the main exotic forest tree planted throughout the country. Since then it has formed at least 50 per cent of all State planting and the greater part of all other planting. The large areas established during 1925–35 are now yielding substantial quantities of wood which, within recent years, have contributed greatly to the industrial development of forest products in this country. What was once considered to be a low-grade, comparatively poor wood has now been proved to have many virtues. It forms an excellent, long-fibred pulp, and when knot-free logs are grown, the timber cut from them is good and the logs are readily peeled for veneer. Although the wood is usually all sap, it can easily be impregnated with preservative.
The great variation of the tree makes it one of the most promising for selection and breeding; it thus gives exceptional prospects of becoming a versatile forest tree throughout New Zealand.
by Alec Lindsay Poole, M.SC., B.FOR.SC., F.R.S.N.Z., Director-General of Forests, Wellington.