December in the hills with Chris Horne
Phyllocladus alpinus agg, mountain toatoa, mountain celery pine
The article in the September 2015 Tramper described Phyllocladus trichomanoides/tānekaha, the largest of the three species in the Phyllocladus genus, then briefly described the other two members of this genus of podocarps.
Origin of the names
Phyllocladus comes from the Greek words ‘phyllon’ meaning ‘leaf’, and ‘klados’ meaning ‘young shoot or branch’, hence ‘leaf-like branches’; alpinus comes from the Latin word meaning ‘belonging to the Alps’; toatoa comes from the plant’s Te Reo name; mountain celery pine refers to the appearance of the cladodes. The suffix ‘agg.’ indicates that mountain toatoa has more than one form.
Distribution and habitat
Mountain toatoa, an endemic small tree, grows in montane forest and subalpine shrubland, usually on rocky sites. On Te Ika a Māui/North Island it occurs from Coromandel southwards to the Tararua Range, but is absent from Mt Taranaki. On Te Waipounamu/South Island, it occurs in the north and in Westland. It is absent from Rakiura/Stewart Island.
True leaves, some linear, up to 15 mm long, and others small and scale-like, occur on seedlings and young plants. These leaves are deciduous, being replaced by what look like fan-shaped leaves, but which are actually flattened branchlets called cladodes or phylloclades that function as leaves. Hence the genus name Phyllocladus, which means ‘leaf-like branches’, making the members of this genus unique among our endemic conifers.
Mountain toatoa/mountain celery pine is the smallest and most cold-tolerant in the genus. It is a shrub or small tree up to 12 m tall, with a short trunk up to 40 cm diameter and smooth bark.
There are two forms of mountain toatoa:
The common form, up to 9 m tall, grows in high-altitude forest and sub-alpine shrublands. Another form up to 12 m tall, grows at middle altitudes in the North Island. In the northern South Island and in Westland it is a common small tree in lowland forests.
Both forms can form patches if their lower branches touch the ground and develop roots. Each season, the small true leaves are replaced by a cluster of cladodes attached along the twigs. They are thick, leathery, often with a greyish waxy tinge and 5-25 mm long x 3-12 mm wide. Their edges may have prominent lobes, with or without serrations. The tips may be rounded or pointed.
The two sexes are in separate flowers on the same plant. The bright red pollen cones, 4-6 mm long, are usually in clusters of 2-7 at the end of the stems. The small seed cones, red and fleshy when ripe, are attached to the edges or stalks of the cladodes. They have 1-5 seeds c. 2.5 mm long, with a white aril at the base. Pollen is released in spring and the seed is ripe from late summer to autumn.
Mountain toatoa wood has been used to make a brown or red dye.
Where to find the species near Wellington
Look for mountain toatoa in subalpine forest in the Tararua Range. There are planted specimens in Otari-Wilton’s Bush, and in Percy Scenic Reserve, Petone.