The celery pines (Phyllocladus genus) are long-lived trees and shrubs. Apart from some tiny scales on young twigs or needle-like leaves on the seedlings, they lack leaves. What appear to be their leaves are in fact small, flattened twigs. These are called phylloclades, and resemble celery leaves. These function as leaves and carry out photosynthesis.
In the past, celery pines were grouped into the podocarp family, but today most botanists place them in their own family – Phyllocladaceae. New Zealand has three species, another grows in Tasmania, and one is found in the New Guinea–Philippines region.
Tānekaha (Phyllocladus trichomanoides) is a medium-sized tree found in lowland forests in the northern half of the North Island and the northern tip of the South Island. It grows on a range of well-drained soils, reaching 20 metres in height and 1 metre in diameter on fertile sites. Tānekaha appears in the early stages of forest succession. It regenerates well in the shelter of mānuka and kānuka scrub.
Its branchlets bear two rows of phylloclades with toothed margins. The female cones form on the edges of the phylloclades.
Its wood is the strongest and most flexible of the native conifers. Māori used the white timber for their canoes and houses, and for koikoi (double-pointed spears). They also produced a red dye from its bark. Early European settlers used its wood for marine piles, bridges, railway sleepers, and for props in the northern coal and gold mines.
Toatoa (Phyllocladus toatoa) is a comparatively small tree up to 15 metres in height, with distinctly whorled branches. Trees that grow in the open are conical in outline.
It is common on infertile soils in central forests of the North Island, where it is usually found as a subcanopy tree. It is rare in Northland forests. Toatoa regenerates freely in cut-over or damaged forests, and can live for 500 years.
The wedge-shaped phylloclades of this species are larger, thicker and more leathery than those of the more widespread tānekaha. The phylloclades are blue-green when young. Seeds ripen in the season in which they form, and are spread by birds attracted to their fleshy white stalks. Toatoa forms hybrids with tānekaha and mountain toatoa.
Mountain toatoa (Phyllocladus alpinus) is the commonest celery pine in New Zealand, growing from Hokianga in the north to Bluff in the south. It ranges in size from a small shrub in alpine scrub, where it is most common, to a tree up to 9 metres tall in upland forest.
It has single leathery, blue-green phylloclades at the ends of short branchlets. The phylloclades are variable in shape, 1–4 centimetres long, and lobed.