Podocarpus laetus (montane totara) description

Podocarpus laetus

Hooibr. ex Endl. 1847

Common names

Montane totara (Salmon 1996), thin-bark totara, Hall's totara (Metcalf 2002), tōtara kōtukutuku [Maori] (Simpson 2017). See also the totara, P. totara.

Taxonomic notes

Synonymy:

Podocarpus cunninghamii Colenso 1884,
Podocarpus hallii Kirk 1889,
Nageia hallii (Kirk) Kuntze 1891,
Podocarpus totara var. hallii (Kirk) Pilg. 1903.

There is a natural hybrid with P. totara, Podocarpus × loderi Cockayne 1932.

Until 2015, this species was known variously as Podocarpus cunninghamii or P. hallii, and virtually all of the scientific literature to that time uses one of these two names. It was finally discovered that a specimen described in 1847 as having been collected in Australia was actually a representative of this taxon and the name assigned to that specimen, P. laetus, is now the valid name by reason of priority (Molloy 2015).

Description

Tree to 20 m tall and 125 cm dbh. Bark thin, papery. Branchlets slender, somewhat drooping on juvenile trees. Leaves brown-green; juvenile foliage 3-7 cm long by 3-5 mm wide, linear-lanceolate; adult foliage smaller, 1.5-3 cm long by 3-4 mm wide, narrow-linear to linear-lanceolate, acute to acuminate, coriaceous, pungent, the midvein usually evident. Pollen cones are 1-2.5 cm long, solitary or up to 5 on a common peduncle, with 4 scales, apiculus obtuse; falling soon after pollen is shed. Ovules solitary or paired; receptacles usually red, swollen and succulent. Seed green, 3-5 mm long, narrow-ovoid, pointed, nutlike (Allan 1961, Metcalf 2002, pers. obs. 2003).

Metcalf (2002) asserts that it is most easily distinguished from P. totara, with which it often grows, by its thin and rather papery bark as opposed to the tough, thick and fibrous bark of P. totara. Matsui et al. (2004) generally agree with that, but present evidence of exceptions; as usual, a confident identification is based on a variety of characters.

Distribution and Ecology

New Zealand: N Island, S Island and Stewart Island (Farjon 1998). Based on data from 1456 collection localities, its climate preferences include a mean annual temperature of 9.2°C, with an average minimum in the coldest month of -0.8°C, and a mean annual precipitation of 2539 mm (Biffin et al. 2011, Table S5). Hardy to Zone 8 (cold hardiness limit between -12.1°C and -6.7°C) (Bannister and Neuner 2001).

Both this and P. totara are tall, slow-growing forest trees that often grow together in lowland forests from sea level to 600 m, with P. totara giving way to P. hallii above 480 m (Salmon 1996). I have seen it growing in what appear to be two distinct ecological niches in the North Island. The first role is that of montane totara, where it grows as a forest dominant on well drained soils at elevations above 480 m. The second role is that of a codominant tree tolerant of wet soils, in which capacity it grows on very wet substrates at low elevations throughout much of Northland. Examples include trees growing on wet floodplain soils in Waipoua and Trounson Kauri Forests, and trees growing very near mangroves around Auckland.

Remarkable Specimens

The largest reported was a tree 30 m tall and 265 cm dbh, the 'Motu totara,' in Dean Forest, Southland (Burstall and Sale 1984). The oldest was recorded by Smale and Smale (2003), studying forest dynamics and tree growth rates, who found ages of up to 496 years for trees growing in native forest remnants at Waihaha in the central North Island. Ages in this study were determined by simple ring-counts of increment cores taken at breast height.

Ethnobotany

See Conifers of New Zealand for a review of the historic role of forests in native and European cultures of New Zealand. Those impacts substantially affected this species.

The bark "was formerly used by southern Maori to encase the kelp bags used for storing muttonbirds. These containers are known as pohatiti" (Metcalf 2002).

In dendrochronological research, this species has been used in at least one climate change study (Burrows and Greenland 1979), and was probably the first New Zealand species to see any dendrochronological use, in an investigation of Maori archeology (Batley 1956).

Observations

In Tongariro National Park it grows on the track up Hauhungatahi, a subsidiary cone west of Mount Ruapehu. To reach this stand, drive 5.5 km south from the highway junction in National Park to the tiny hamlet of Erua and park near the railroad tracks. Follow the tracks about 250 m south to where a small, weathered sign says 'Track' and follow it. The track heads almost continuously uphill, starting in a flax thicket and then, in the forest, passing progressively through elevation zones dominated by rimu (Dacrydium cupressinum), matai (Prumnopitys taxifolia), montane totara (Podocarpus laetus), kaikawaka (Libocedrus bidwillii), yellow pine (Halocarpus biformis), mountain toatoa (Phyllocladus alpinus), bog pine (Halocarpus bidwillii) and pygmy pine (Lepidothamnus laxifolius). This species can also be seen growing along an elevational sequence along the Tongariro Crossing, above the Ketetahi trailhead. As noted above, it also grows in very wet soils in Northland; good examples can be seen in Trounson Kauri Forest, along the ridge walk in Puketi Forest, and along the walk to Te Matua Ngahere (the biggest kauri) in Waipoua Forest.

Remarks

The epithet laeta means joyful or happy, but the relevance to this species is unclear.

Citations

Allan, H. H. 1961. Flora of New Zealand. Volume I, Indigenous Tracheophyta. Wellington: R.E. Owen Government Printer.

Batley, R. A. L. 1956. Some practical aspects of dendrochronology in New Zealand. Journal of the Polynesian Society 65(3): 232-244 (as Pinus hallii).

Cockayne. 1932. Conifers in Cultivation: the Report of the Conifer Conference held by the Royal Horticultural Society, Nov. 10–12, 1931, ed. by F. J. Chittenden: p. 161.

Endlicher, S. L. 1847. Synopsis Coniferarum. Scheitlin und Zollikofer, Sangalli (Sankt Gallen). P. 214. Available: Biodiversity Heritage Library, accessed 2022.12.23.

Molloy, Brian. 2015. The correct name for the New Zealand endemic conifer Hall’s totara (Araucariales: Podocarpaceae). Phytotaxa 220(2):101-116.

Simpson, Philip. 2017. Totara: A Natural and Cultural History. Auckland University Press, 300 pp.