Scientific name: Phyllocladus toatoa Molloy 1996

Synonyms: Phyllocladus glaucus Kirk

Common names: Blue celery pine, Toatoa (Maori)

Description

Tree to 12(-25) m tall, with a cylindrical, rapidly tapering trunk to 0.4(-0.9) m in diameter. Bark thin, smooth at first with a scattering of warty lenticels and irregular, horizontal, low ridges, dark brown weathering grayish brown to silvery brown, flaking in rectangular scales to reveal dark orange patches and finally becoming deeply furrowed. Crown conical at first, becoming irregularly cylindrical to dome-shaped with age, with whorls of stout, generally strongly upwardly angled branches and many scattered, late developing, extra branches between the regular flushes. Phylloclades attached singly or in rings of (2-)5-7(-10) at the tips of growth increments, compound, (5-)12-20(-30) cm long overall (down to 1.5 cm in juveniles), with 5-10(-14), predominantly alternately pinnate segments. Each segment 2-5(-8) cm long, roundly diamond-shaped to fan-shaped, roundly and shallowly toothed (sharply toothed in juveniles) to deeply lobed, more or less yellowish green above and thinly to prominently waxy bluish green beneath. Juvenile leaves (5-)10-15 mm long. Scale leaves of adult long shoots and buds (0.5-)10-15(-20) mm long. Plants predominantly dioecious but individuals of one sex often with a few cones of the other. Pollen cones single or, more frequently, in clusters of (5-)10-20 at the tip of a short branchlet or at the base of a growth increment. Each pollen cone (1-)1.5-2.5(-3) cm long, 4-7(-10) mm thick, yellowish brown to pink or brownish red just before shedding pollen, on a long, heavy stalk 5-10(-15) mm long. Seed cones in open groups of (three or) four to seven (or eight), each individually replacing a lower phylloclade segment. Each seed cone spherical to a little elongate, (5-)7-13 mm long, 5-9 mm in diameter, with 10-20(-25) bracts of which 8-20 are fertile and mature (1-)3-15(-20) seeds. Bracts swollen, juicy, pinkish red to brownish red at maturity. Seeds hard, shiny dark brown to black, (2-)3-4 mm long, enclosed for about half their length by the thick white aril.

For more than 125 years and following the lead of New Zealand forest botanist Thomas Kirk, this species was mistakenly called Phyllocladus glaucus. The name Phyllocladus toatoa was proposed in 1996 for this long-known species because the type specimen of Phyllocladus glaucus actually came from a cultivated Tasmanian celery-top pine (Phyllocladus aspleniifolius), the only species of Phyllocladus that had introduced to Europe by 1855. Consequently, the taxon known by its Maori name Toatoa was in need of a new species name, for which Molloy chose to use the native name.

Northern two-thirds of North Island and some adjacent offshore islands, New Zealand. Scattered or, less commonly, somewhat gregarious in the understory of mixed lowland and montane forests and in the canopy of stunted forests and scrublands on exposed ridges, usually on damp to wet substrates; 0-600(1,000) m.

Conservation Status

Red List Category & Criteria: Least Concern

Despite the historical reduction of the forests in which this species occurs, which had led to fragmentation of the population, the sites in which it still occurs are numerous across its (historical) extent of occurrence. Estimating the area of occupancy with a (generous) width of 10 km for each locality mapped (based on herbarium specimens) it could be Near Threatened. However, it is definitely now increasing instead of declining, so Least Concern is the appropriate category.

Phyllocladus toatoa occurs in mixed subtropical to warm temperate rainforest from near sea level to 600 m a.s.l. It is a minor constituent of the Kauri forest (Agathis australis) which is dominated by conifers, with as many as eight species per hectare in some places. In podocarp-hardwood forest where angiosperms usually dominate, it will be restricted to poorer sites. Much of this forest has gone and the remnants are often opened up by past logging of bigger trees, leaving a more open secondary growth in which Phyllocladus toatoa, being a sub-canopy tree in mature tall forest, has a better chance to thrive.

Logging and forest clearing were the main threats to this species, but have now ceased. The wood of Toatoa or Blue celery pine is nearly white, straight grained and strong; it is used for furniture, but being rare and now protected from commercial exploitation not of economic importance. It is only cultivated in some botanic gardens in mild climate regions, but should be an ideal small tree for horticulture with its bright bluish young phyllodes of new growth.

New Zealand government policy protects native stands of trees both in state owned reserves and on private land. This species does not need special conservation action beyond this, as it actually benefited from logging the bigger trees in many forests.

References

Farjon, A. (2010). A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Eckenwalder, J.E. (2009) Conifers of the World: The Complete Reference. Timber Press, Portland.
IUCN Red List of Threatened Species, International Union for Conservation of Nature and Natural Resources. Cambridge, UK /Gland, Switzerland