Tuatara: Volume 4, Issue 3, September 1952
New Zealand Conifers — A Note on Their Uses and Importance
New Zealand Conifers
A Note on Their Uses and Importance
The conifers native to this country range in size and importance from the giant Kauri — one of the most valuable timber trees in the world — to the little heath-like Pygmy Pine of the mountain herbfield, and include a variety of species which provide fine timbers and some which make noble ornamental trees. They are to be found in almost every scrub and forest community from North Cape to Stewart Island, but no longer grow on any of the outlying islands. In the following list the numbers correspond with those of the illustrations, and the common names are given also.
1. Agathis australis — the Kauri — provides a timber which far excels that of any other conifer in its combination of great size and high quality. The trees have smooth pale-grey massive columnar trunks, rising without taper to a height of 80 to 100 feet and each topped by a head of stout spreading branches. The bark scales off in large flakes, forming a characteristic mound of litter about the base of each tree. The timber is yellowish-white to golden-brown, silky, straight-grained, even and compact, of great strength, toughness, elasticity and durability. It is available in large broad lengths free from knots and flaws, and owing to its comparative rarity nowadays its use is restricted to such purposes where this quality is necessary, though formerly it was used for every building purpose. It splits readily into straight slabs, is easily worked, and holds nails and screws well. Waved and mottled kauri is prized for ornamental work, and is often obtainable in large pieces.
The two species of Libocedrus are so much alike in appearance, both in the old and in the young trees, that it is very difficult to tell one from the other. Both are quite tall trees with short broad conical heads and straight naked trunks from which the old bark falls away in long thin ribbons. In both the juvenile form is a graceful small tree with flattened feathery branchlets:
2. Libocedrus bidwillii — the Pahautea, or Mountain Cedar (often known by the bushman's incorrect name of Kaikawaka) — has dark red timber, light but very durable, with a straight but rather short grain and uniform texture without any variegation such as is found in L. plumosa. It is readily split into thin slabs and its durability is shown by its successful use for shingles and weatherboards in earlier times; but it cannot be used for beams or floor joists because of its brittle nature. In all these characters it is similar to the Californian Redwood.
3. Libocedrus plumosa — the Kawaka — has a more handsome pyramidal page 109 juvenile form, which is widely used as an ornamental tree. The branchlets in the adult are more flattened than in L. bidwillii (whose branchlets are square in cross-section). The timber is dark red with darker streaks and is often beautifully variegated. It has all the qualities of Pahautea timber and in addition is stronger. It is too rare for general use, so is mainly kept for cabinet-making and ornamental work.
Of the Podocarps, the first two species dealt with are shrubs whose trunks and branches are much too small to be of value as timber:
4. Podocarpus nivalis — the Snow Totara — is a low spreading bush with prostrate rooting branches, forming broad flattened masses in subalpine localities.
5. Podocarpus acutifolius — the Needle-Leaved Totara — is a bush with erect branches; the leaves are sharp and prickly to handle.
The next two species are very similar in appearance, although, as the key shows, there are some well-marked differences. The timbers are similar in almost every respect, and are known collectively as Totara. It is the most valuable timber next to Kauri, the tall massive trunks giving wide lengths of straight clean timber which is nearly all heart-wood:
6. Podocarpus totara — the Totara: — Timber pink to dull red, straight-grained, readily splitting into slabs, extremely durable. It does not warp or twist and it holds nails and screws very well, consequently it is much used for door and window frames and sills. It requires a special priming paint because the high resin content prevents drying of ordinary paints. The heart timber is completely resistant to the attack of the marine borer (Teredo), and is used for wharf piles and sheathing of boats. Although it is so durable it is inclined to be brittle, especially when old, and if used as cross-beams is liable to break suddenly and without warning. For uprights it is excellent, but fence-posts of totara are liable to snap under sudden strain. Excrescences on the tree trunk contain the prized Totara Knot used for inlaying and veneers. It has the appearance of curly maple, deep red in colour.
7. Podocarpus hallii — the Thin-Bark Totara — Trees usually smaller than Totara, timber said to be slightly denser and slightly less resistant to Teredo, but otherwise exactly the same.
The next two species, though both having grey-black ‘hammer-marked’ bark, foliage of similar appearance, and hard timber of fairly similar colour (so that both are called ‘Black Pine’), have different qualities which cause their timbers to be suitable for different purposes:
8. Podocarpus ferrugineus — the Miro — is a tall round-headed tree with pale to dark grey-brown timber of which the heart-wood is very dark and usually has a blackish edge at its junction with the sap-wood. The grain is straight and even, and the wood hard, elastic and very strong — the strongest of all the native conifers — but it is not at all durable where water can reach it, or in contact with the ground. It is less easily worked than some of the other timbers, being inclined to split when nails are driven in, but owing to its great strength and elasticity it is especially valuable for cross-beams to carry great weights. It also makes excellent flooring.page 110
9. Podocarpus spicatus — the Matai — is also a tall, round-headed tree. The timber is pale to rich-brown, straight and even, fine-textured, hard and heavy. It makes the best possible flooring because of its hardness, is exceedingly durable in contact with the ground, and is very strong, though better used for uprights than for cross-beams as it has a tendency to be brittle.
10. Podocarpus dacrydioides — the Kahikatea or White-Pine — is a very tall tree with pale-grey, ‘hammer-marked’ bark and a straight bare trunk providing broad lengths of knot-free timber. Both sap-wood and heart-wood are white, becoming pale-yellow, the heart-wood being more dense and sometimes quite bright yellow. The timber is straight and even in grain, very easily worked, light but fairly strong and tough, though the sap-wood is not at all durable and decays rapidly in damp places or from borer attack. In spite of this it is very valuable, its chief use being for vats, cases, etc., in the dairy industry, since it is perfectly odourless. The heart-wood is more durable, and is useful as a substitute for Kauri in boat-building.
The first two Dacrydium species listed are mountain shrubs with no timber to speak of; the others are important timber trees:
11. Dacrydium laxifolium — the Pygmy Pine — is a small plant, scarcely even a shrub, with slender, flexuous trailing branches. It is very similar in appearance to the small heath Cyathodes empetrifolia, but the latter differs in having glaucous backs to the leaves.
12. Dacrydium bidwillii — the Bog-Pine or Mountain-Pine — is a conical or dome-shaped shrub or small tree with a very short trunk and stout rigid pale-grey branches, the lowermost of which are sometimes prostrate and rooting. It is usually found in mountain bogs, and its closely-branched symmetrical habit makes it an attractive garden plant.
13. Dacrydium cupressinum — the Rimu or Red-Pine — is a large tree, easily recognized by its weeping branchlets which give it an appearance quite different from that of any other native tree. The bark is grey-brown and scales off in large flakes. The heart timber is reddish to yellowish brown, richly figured with irregular lighter or darker streaks, and takes a high polish. There is an intermediate zone which is uniform pale biscuit-brown, and the sap-wood is paler still. The heart timber is strong and elastic, quite hard, durable close to but not in contact with the ground, and quite easily worked though inclined to split when nailed. The intermediate and sap woods are softer and much less durable, but are of high value for furniture-making and for ‘peeling’ for plywoods and veneers. Rimu is a good all-round building timber. It is often used for the main timbers of bridges, but is not satisfactory since water enters the cracks which have developed during growth or which open under weathering, and soon causes decay, so that such timbers have to be replaced in seven to fourteen years. As fence-posts, too, it is liable to decay or to become brittle in a few years. The young tree is most graceful and beautiful, with very long weeping branchlets, and is valuable as an ornamental tree.page 111
The next two species are small conical trees, practically indistinguishable from each other in the absence of fruit, and with wood of very similar properties though differing slightly in colour. Their common names refer to wood colour. Although the timber in both species is of small dimensions, it is highly valuable as being the most durable of all native conifers — excelled only by Puriri and Pohutukawa among the other native trees. In both the wood is very resinous and inflammable, dangerous for firewood on account of the flying sparks; but the beautiful scent of the burning logs is unforgettable:
14. Dacrydium colensoi — the Silver-Pine — Timber white at first, becoming yellowish, distinguished from Kahikatea by the greasy feel caused by resinous crystalline deposits, and by the very close growth rings. It is very strong, tough and elastic, extremely durable, dense and usually straight in the grain, but sometimes waved and figured. It takes a high polish with a satiny lustre. Mottled pieces are prized for inlay work, being of similar appearance to Totara Knot but of pale-gold colour. The commonest uses for Silver-Pine are in boat-building and as marine piles, mine props, sleepers and fence posts. The latter are liable to snap after some years, but do not rot. Kirk recommends this timber for the making of furniture and agricultural implements.
15. Dacrydium intermedium — the Yellow Silver-Pine, or Yellow-Pine:— Timber similar in all qualities to that of Silver-pine, but of a reddish- yellow colour.
The next two species share the peculiarity of retaining juvenile foliage in the adult tree, so that the same branch, even the same twig, may show two very different types of foliage, as though a plant with ‘whip-cord’ branchlets were growing parasitically on one whose branchlets are clothed with long flat spreading leaves:
16. Dacrydium kirkii — the Monoao — is a tall conical tree in which the lower branches bear mostly large leaves and the upper branches mostly small imbricating leaves. The timber is pale whitish-brown, dense, strong, elastic and very durable, capable of taking a high polish. It is thus a valuable timber, but the trees are rare. The Monoao makes a fine ornamental tree.
17. Dacrydium biforme — the Pink-Pine — retains the juvenile leaves only on young adult trees, or on shoots from the trunk of an old tree. It is a small tree, often reduced to a shrub in mountain regions. The timber is yellowish-brown, straight-grained and even, with a silky texture, easily worked and very strong and durable when used as posts and sleepers.
The last group of species are those known as ‘celery pines’, in which the true leaves are reduced to minute points while the branchlets bearing them are flattened, green and leaf-like, with a characteristic leathery texture. The bark in all three species can be used for tanning; the red dye from that of Tanekaha in particular was much used by the Maoris:
18. Phyllocladus alpinus — the Mountain Toa-Toa — is a bush or small tree of mountain districts. The timber is white, and though of small dimensions and not durable, is very strong, tough and elastic.page 112
19. Phyllocladus trichomanoides — the Tanehaka — is a tall graceful tree with a straight trunk and slender branches produced in whorls. The timber is white, straight-grained, dense and heavy, of great strength, toughness, elasticity and durability, and is available in good lengths free from knots and defects. The Tanekaha is a most beautiful ornamental tree.
20. Phyllocladus glaucus — the Toa-Toa — is a handsome small tapering tree with stout whorled branches. The timber is similar to that of Tanekaha — white, straight-grained, strong, tough and elastic — but is more knotty owing to the stout branches. The Toa-toa is comparatively rare in nature, but is easily transplanted and is a favourite ornamental tree.
Key to the Genera
|1||Leaves spirally arranged on twigs||— 2|
|Leaves not spirally arranged||— 5|
|2||Leaves scale-like, overlapping||— 3|
|Leaves not scale-like, not overlapping||— 4|
|3||Leaves markedly of two distinct types, older leaves closely appressed, angular on back, with scattered lines of stomata; apex acute or obtuse||Darrydium|
|Leaves less distinctly of two types, slightly spreading, convex and keeled on back, without visible lines of stomata; apex with short sharp terminal point, incurved (dacrydioides)||Podocarpus|
|4||Leaves leathery, up to 2 cm. long, margins flat, points sharp or blunt||Podocarpus|
|Leaves replaced by flattened branches (cladodes) which resemble leaves||Phyllocladus|
|5||Leaves large, alternate, with many parallel veins, and resin canals between||Agathis|
|Leaves small, opposite and in pairs alternately at right angles, scale-like, with 2 lateral furrows on lower surface||Libocedrus|
Key to the Species
|1||Mature plant a shrub||—2|
|Mature plant a tree||—5|
|2||Leaves 1-2 cm. long||—3|
|Leaves less than 0.5 cm. long||—4|
(All half natural size)
Fig. 1: Agathis australis (Kauri). Fig. 2: Libocedrus bidwillii (Mountain Cedar): (a) adult, (b) juvenile. Fig. 3: Libocedrus plumosa (Kawaka): (a) adult, (b) juvenile. Fig. 4: podocarpus nivalis (Snow Totara). Fig. 5: Podocarpus acutifolius (Needle-leaved Totara). Fig. 6: Podocarpus totara (Totara). Fig. 7: Podocarpus hallii (Thin-bark Totara). Fig. 8: Podocarpus ferrugineus (Miro). Fig. 9: Podocarpus spicatus (Matai): (a) adult, (b) juvenile.
|3||Leaves thin, tapering to a point, linear-lanceolate||(Fig. 5) Podocarpus acutifolius|
|Leaves thick and leathery, obtuse or abruptly acute, linear oblong||(Fig. 4) Podocarpus nivalis|
|4||Branches slender, lax, prostrate; mature leaves oblong and spreading||(Fig. 11) Dacrydium laxifolium|
|Branches stout, rigid, erect or prostrate; mature leaves triangular and closely appressed||(Fig. 12) Dacrydium bidwillii|
|5||No distinct juvenile leaf form||— 6|
|Distinct juvenile leaf form, juvenile leaves larger and spreading, adult leaves smaller and overlapping||— 15|
|6||Leaves 1 cm. broad. 2-6 cm. long, very thick and leathery, cones large, orbicular||(Fig. 1) Agathis australia|
|Leaves and cones otherwise||— 7|
|7||Leaves linear, spreading||— 8|
|Leaves of a different form||— 11|
|8||Bark greyish black; fruit drupe-like; peduncle not swollen and fleshy||9|
|Bark pinkish; fruit a nut seated on a swollen or fleshy peduncle||— 10|
|9||Leaves glossy, bright green, sickle-shaped; fruit reddish-purple with a bluish green bloom||(Fig. 8) Podocarpus ferrugineus|
|Leaves dull green, not sickle-shaped, fruit black||(Fig. 9) Podocarpus spicatus|
|10||Bark thick, stringy; leaves linear-oblong||(Fig. 6) Podocarpus totara|
|Bark thin, flaky; leaves linear-lanceolate||(Fig. 7) Podocarpus hallii|
|11||Leaves minute, appressed, overlapping||— 12|
|Leaves replaced by broad flat cladodes||— 13|
|12||Branches spreading; branchlets arranged in two vertical rows||(Fig. 3) Libocedrus plumosa|
|Branches parallel, clustered and erect; branchlets having four angles||(Fig. 2) Libocedrus bidwillii|
|13||Cladodes not pinnately arranged||(Fig. 18) Phyllocladus alpinus|
|Cladodes pinnately arranged||— 14|
|14||Cladodes 1-2.5 cm. long||(Fig. 19) Phyllocladus trichomanoides|
|Cladodes 2-7 cm. long||(Fig. 20) Phyllocladus glaucus|
|15||Juvenile leaves 5-10 times as long as adult leaves, both kinds occurring on same branch of adult tree||— 16|
|Juvenile leaves less than 3 times as long as adult leaves, confined to lowermost branches of adult tree||— 17|
(All half natural size)
Fig. 10: Podocarpus dacrydioides (Kahikatea): (a) adult, (b) juvenile. Fig. 11: Dacrydium laxifolium (Pygmy Pine). Fig. 12: Dacrydium bidwillii (Bog Pine). Fig. 13: Dacrydium cupressinum (Rimu): (a) adult, (b) juvenile. Fig. 14: Dacrydium colensoi (Silver Pine). Fig. 15: Dacrydium intermedium (Yellow Pine). Fig. 16: Dacrydium kirkii (Monoao). Fig. 17: Dacrydium biforme (Pink Pine).
|16||Juvenile leaves 2-4 cm. long||(Fig. 16) Dacrydium kirkii|
|Juvenile leaves 1-2 cm. long||(Fig. 17) Dacrydium biforme|
|17||Fruit a 4-valved woody cone||— 18|
|Fruit a nut||— 19|
|18||Adult branches horizontal or drooping||(Fig. 3) Libocedrus plumosa|
|Adult branches ascending singly or in parallel groups||(Fig. 2) Libocedrus bidwillii|
|19||Nut seated on red fleshy peduncle||— 20|
|Nut seated in a membranous, cup-like aril||— 21|
|20||Branchlets pendant||(Fig. 13) Dacrydium cupressinum|
|Branchlets erect||(Fig. 10) Podocarpus dacrydioides|
|21||Nuts solitary, pointed, 5-7 mm. long; wood yellowish-red||(Fig. 15) Dacrydium intermedium|
|Nuts in pairs, blunt, 4-5 mm. long; wood yellowish-white||(Fig. 14) Dacrydium colensoi|
- aril — cup-shaped expansion of ovule stalk.
- drupe — fleshy or succulent fruit with seed in hard kernel.
- peduncle — swollen structure supporting fruit.
The writers are indebted to Mr. A. L. Poole for the use of key characters from his unpublished manuscript, and to Dr. H. H. Allan for use of a generic key adapted from Fitzpatrick (1929). The assistance of Miss L. B. Moore, Miss P. A. Lush, and Mr. J. S. Reid is also gratefully acknowledged.