II. The New Zealand Podocarps

The Mystery that is the 'Podocarp'

 

The New Zealand podocarps are for me one of the most confusing groups of trees I have come across. I kept seeing references in guide books, leaflets and interpretational signage to these things called 'podocarps' but they never said what they were.

 

And the strange 'podocarps' have even stranger Maori names - totara, rimu, matai, miro and kahikatea - that are then rendered into translations that all include the word 'pine'.

 

This was the settler way of making sense of difference and dominating the threatening Other by forcing its difference into the familarity of classifications that had come from the known and safer (at least in some ways) Mother Country.

 

But this juxtaposition and elision of the familiar and exotic that signals an uneasy truce between colonial (European) and post-colonial (Maori/Pacifika/Pakeha) discourses makes it hard sometimes to understand what the hell is going on.

 

That is exemplified in the 'podocarp' which is exotic, different, unique, ancient and yet is reduced to the familiarity of names such as 'White', 'Black', 'Yellow' and 'Yellow Silver' Pine.

 

But the whole thing about the podocarp is that while it is part of the very wide plant division of 'conifers' it is not a pine as we would understand it in the Northern hemisphere.

 

Why is that? Because it doesn't have pine cones and it doesn't have pine needles as your northern hemisphere logger would understand them. Indeed, that is what 'podocarp' precisely eludes to in its obscurantist latinate naming system.

 

For podocarp literally means 'foot-seed' where the seed of the female plant (unhelpfully the podocarp is also diecious - comprised of distinct male and female trees) lies below the fruit of the tree rather than  - as is the case in the northern hemisphere pine - being enclosed by it (in a pine cone).

Kahikatea seeds (the blue spheres)with their characteristic orange to red arils that attract birds to eat the seed for its dispersal. Photographed at the Arataki Visitor Centre in the Waitakere Region
Kahikatea seeds (the blue spheres) show the charachteristic of the podocarp where the seed sits at the foot (pied/pod) of the fruit.

The large podocarpaceae family is a member of the conifer (Pinophyta) division of plants.The conifers are part of the gymnosperms (gymno - naked/ sperm - seed) that evolved 350 million years ago and before the flowering plants (the agniosperms - vessel-seeds).

 

The conifer family members in New Zealand are:

  • the podocarps (eight genera and 14 species)
  • the Araucariaceae family containing one species - the kauri (Agathis australis)
  • the celery pines (Phyllocladaceae with three species)
  • the cypress (Cupressaceae with two species)

 

The podocarp family has the most genera and species of the conifer division in New Zealand.

Phylogeny of the conifer (Pinaceae) division showing relationship of Araucariaceae (New Zealand kauri) and podocarpaceae (from Wikipedia: Araucariaceae).
Phylogeny of the conifer (Pinaceae) division showing relationship of Araucariaceae (New Zealand kauri) and podocarpaceae (from Wikipedia: Araucariaceae).
Rimu foliage from tree at Te Waikoropupu Springs, Golden Bay.
Rimu foliage from tree at Te Waikoropupu Springs, Golden Bay.

'Podocarpaceae is a large family of mainly Southern Hemisphere conifers, comprising about 156 species of evergreen trees and shrubs' (Wikipedia) containing 19 genera. Members of eight of these genera occur in New Zealand.

 

The family [which] ... shows great diversity, both morphologically and ecologically ... is a classic member of the Antarctic flora [originating from the supercontinent of Gondwana], with its main centres of diversity in Australasia, particularly New Caledonia, Tasmania and New Zealand, and to a slightly lesser extent Malesia and South America.

 

Within the family podocarpaceae there are eight genera extant in New Zealand. These are:

  • Podocarpus - the five species of Totara
  • Dacrydium - the Rimu is the only species in New Zealand
  • Prumnopitys - the Miro and Matai
  • Dacrycarpus - the Kahikatea is the only New Zealand species
  • Halocarpus - the Bog and Yellow Pine
  • Lepidothamnus - the Yellow-silver and Pygmy Pines
  • Manoao - the Silver Pine

 

The kauri is not a podocarp but a genus (Agathis) that belongs to the ancient Araucariaceae family of conifers (that includes the Chilean 'Monkey Puzzle').

 

(Sources for these pages include Wikipedia, the New Zealand Plant Conservation Network, the Taranaki Educational Resource: Research, Analysis and Information Network and the Gymnosperm Database. Many thanks to all three of them for the excellent information.)

Kahikatea (Dacrycarpus dacrydioides) 'White Pine'

Etymology: Dacrycarpus = tear-shaped fruit

 

Kahikatea swamp forests on the West Coast like that at the southern end of  Lake Ianthe/Matahi are 'the nearest replica of the type of primeval forest that would have existed 80 million years ago at the time of separation from Australis' (Gibbs Ghosts of Gondwana). Once called 'white pines' they differ from pines because they do not have woody pine cones. Instead, their female cones are reduced to single scales that ripen into solitary seeds surrounded by or sitting on brightly coloured, fleshy structures that attract birds (Te Ara).

Dacrycarpus dacrydioides or kahikatea (once mistakenly called 'white pine' ) at the water's edge of Lake Inathe/Matahi. The seed covers (aril) were eaten by Maori and heartwood charcoal was used to ma
Dacrycarpus dacrydioides or kahikatea (once mistakenly called 'white pine' ) at the water's edge of Lake Inathe/Matahi. The seed covers (aril) were eaten by Maori and heartwood charcoal was used to make a tattooing (ta moko) pigment

The kahikatea has separate male and female (dioecious) trees and is New Zealand's tallest tree. It can grow up to 55 metres (180 ft) (a living specimen achieved 62.57 metres in 1996/7) and live for 500 hundred years. Of the New Zealand podocarps it can be traced furthest back into the fossil record - perhaps to Mesozoic period 200 MYA (RFBP: 50).

 

The trees grow in wet ground on lake and river marshes. They can support themselves through their interlocked root mats on semi-liquid peat. The spongy roots 'enable them to oxygenate their rootlets and thus survive in waterlogged soils that few other trees can tolerate' (Forest, Fiords and Glaciers RFBP p.50).

Lake Ianthe/Matahi Kahikatea  forest between Franz Josef Glacier and Hokitika
Lake Ianthe/Matahi Kahikatea forest between Franz Josef Glacier and Hokitika

Kahikatea forest is increasingly rare, particularly in the North Island, where it was cleared for its timber (it has no odour and although not very durable was excellent for butter boxes) (see here for the 'slaying of the kahikatea') and for the flat farmland that could be developed from drained marshes. In the South Island acreages of dense kahikatea stood at 4,500Ha in 1987 and it is said to be 'as scarce as kauri' and more vulnerable to logging due to a lack of protection (ibid p.50).

 

The seed covers (aril) ('koroi' in Maori) were eaten by Maori and heartwood charcoal was used to make a tattooing (ta moko) pigment (Wikipedia).  The seeds only occur on the female tree.

 

'A large mature kahikatea yielded 300 pounds (136 kg) of sound seed, representing 4.5 million seeds' (Gymnosperm Database). This is important food for tui, bellbirds and kereru (pigeons).

Kahikatea seeds (the blue spheres)with their characteristic orange to red arils that attract birds to eat the seed for its dispersal. Photographed at the Arataki Visitor Centre in the Waitakere Region
Kahikatea seeds (the blue spheres) show the charachteristic of the podocarp where the seed sits at the foot (pied/pod) of the fruit.

Bark dark grey, covered irregularly with small protuberances ca. 1-2 mm across and 1-2 mm high, scaling off in large, ovoid flakes.

Kahikatea with submerged roots in Arohaki Lagoon
Kahikatea with submerged roots in Arohaki Lagoon (Courtesy Pseudopanax WikiCommons)

Matai (Prumnopitys taxifolia) 'Black Pine'

Perhaps majestic matai tree (Prumnopitys taxifoliatree), an outlier of the forests that once covered Whataroa Flats, Westland.
Majestic matai tree (Prumnopitys taxifoliatree), an outlier of the forests that once covered Whataroa Flats, Westland. Ballyhooly Bush in Lower Whataroa is one of the remnant matia/totara forests (16 stands with largest at 67ha) on the West Coast.

Etymology: Prumnopitys: From the Greek prymnos 'hindmost' or 'stern' and pitys 'pine', referring to the location of the resin duct. Taxifolia - like yew leaves - taxus in Latin.

 

We passed by a majestic matai tree 'Black pine' (Prumnopitys taxifoliatree) on the Whataroa Flats. It has a thicker, fluted trunk that the kahikatea and is part of the podocarp family. It grows to 25-30 m tall and the trunk is 1-2 m in diameter.

 

Its seeds are dispersed by the Kereru/New Zealand Pigeon (Hemiphaga novaeseelandiae). It feeds on the matai berries and thus disperses them. It is a different genus from the European Wood Pigeon. 

 

The hard timber of this tree was used extensively for flooring during the mid-20th century.  Very few intact Matai-dominated forests remain (Te Ara).

 

With a broad crown on stout upright spreading branches it grows on the North Island and South Island. It also occurs on Stewart Island/Rakiura (47 °S) but is uncommon there. It grows up to 33 m high, with a trunk up to 2.35 m diameter and is thought to have a life span of a 1000 years.

 

Matai prefer well-drained flood plains and deep pumice deposits, and at one  time matai/totara forests occurred throughout New Zealand.

 

'Both matai and totara can produce new root systems from their trunks after silt is deposited around them' (see McSWEENEY: MATAI/TOTARA FOREST IN SOUTH WESTLAND, NZJEcol 5 1982 p. 125).

 

Matai is not threatened, although as a forest-type it has been greatly reduced through widespread logging. It also tends to occur on the best alluvial agricultural land (see TERRAIN).

Matai leaves (Prumnopitys taxifolia) that resemble the European Yew (Taxus) (Courtesy Kahuroa WikiCommons)
Matai leaves (Prumnopitys taxifolia) that resemble the European Yew (Taxus) (Courtesy Kahuroa WikiCommons)

Mataī has a distinctive and long-lasting juvenile stage unlike the related Miro (Prumnopitys ferruginea). The juvenile is a shrub with a tangle of slender, flexible, divaricating branchlets interspersed with a scattering of brown, pale yellow, or dirty white leaves. After a number of years, the adult tree begins to grow out of the top of the juvenile shrub and then the divaricating branchlets will wither and drop off.

 

Wikipedia: Matai quote

 

This was a defence against browsing by birds, particularly the now extinct Moa. Divarication appears to be a particular evolutionary response in a New Zealand absent of mammal browsers (see Gibbs Ghosts of Gondwana pp162-6.) 

 

Once the Matai is above the height of the largest Moa  browser it conforms to a more 'natural' tree-growing strategy.  Putting all its eggs into one basket too early - by only having a central growing tip - might have rendered it  vulnerable to attack, growth-point-splitting and slower growth towards the light in the competitive conditions of scrub and forest clearings.

The plum-like seed of the matai (Courtesy of Te Ara)
The plum-like seed of the matai (Courtesy of Te Ara)

A survey of matai (Podocarpus spicatus) / totara (Podocarpus totara var. waiho- ensis) forest in South Westland recorded that c. 600 ha of these forests remain from a possible former 43,000 ha. (McSWEENEY: MATAI/TOTARA IN SOUTH WESTLAND NZJEcol 5 1983).

 

Matai bark: Grey-brown and punctate, it flakes off in thick rounded or ovoid chunks which leave reddish blotches on the trunk. The bark is commonly described as having a 'hammered' appearance (The Gym
Matai bark: "Grey-brown and punctate, it flakes off in thick rounded or ovoid chunks which leave reddish blotches on the trunk. The bark is commonly described as having a 'hammered' appearance" (The Gymnosperm Database)
A juvenile Mataī is a tangle of divaricating branchlets with occasional brown, pale yellow, or dirty white leaves(Kahuroa: WikiCommons)
A juvenile Mataī is a tangle of divaricating branchlets with occasional brown, pale yellow, or dirty white leaves (Kahuroa: WikiCommons)
Great photo by Phil Bendle at TERRAIN of juvenile stage Matai at Otari Native Botanic Garden (Bendle/TERRAIN - click for link).
Great photo by Phil Bendle at TERRAIN of juvenile stage Matai at Otari Native Botanic Garden (Bendle/TERRAIN - click for link).

Miro (Prumnopitys ferruginea) 'Brown Pine'

Miro trunk and bark (Prumnopitys ferruginea) growing on Ulva Island (part of the Stewart/Rakiura Islands)
Miro trunk and bark (Prumnopitys ferruginea) growing on Ulva Island (part of the Stewart/Rakiura Islands)

Etymology: Prumnopitys (see above)  ferruginea (iron-like, rusty coloured)

 

Grows to 25m, a stout tree, trunk similar to Matai, but foliage supposed to be easily identifiable. Appears finer and more pointed than 'banana-shaped' foliage of Matai. 'The bright green to bronze-green, feathery foliage, and pink-red, to red plum-like drupes are quite unlike any other New Zealand conifer' (NZPCN)

Young Miro leaves (Courtesy Kahuroa WikiCommons)
Young Miro leaves (Courtesy Kahuroa WikiCommons)
Miro seeds (Coutesy Gymnosperm Database)
Miro seeds (Coutesy Gymnosperm Database)

Rimu (Dacrydium cupressinum)

Etymology: Dacrydium: tear drop. Cupressinum: cypress

 

Rimu is longer lived than the kahikatea and can live to 800 years. Slow growing and able to tolerate poor soils, it can develop very dense stands husbanding its nutrient supply in its great bulk and the leaf litter it sheds (Forest, Fiords and Glaciers RFBP p.51).

 

Grows to 35-60m tall. Adult trees have a trunk bare of branches for 3/4 of length. Flaky, dark brown bark. A round-topped crown with strong lateral branches bearing pendulous branchlets and foliage when mature.

 

Bark is dark brown or grey, stringy, usually pimpled, and peels in long, thick flakes

 

Lowland to montane forest - occasionally ascending to subalpine scrub.

Rimu standing above the broadleaf canopy on the Rkiura Track east of Lee Bay on Stewart Island
Rimu standing above the broadleaf canopy on the Rakiura Track east of Lee Bay on Stewart Island. Note characteristic crown branching three-quarters of the way up the trunk.
Rimu foliage from tree at Te Waikoropupu Springs, Golden Bay.
Rimu foliage from tree at Te Waikoropupu Springs, Golden Bay.
Giant rimu trunk on Ulva Island. Rimu (Dacrydium cupressinum) is the commonest and most widely distributed conifer in New Zealand
Giant rimu trunk on Ulva Island. Rimu (Dacrydium cupressinum) is the commonest and most widely distributed podocarp in New Zealand. It supports a wide range or epiphytes.
Seedling Rimu on Ulva Island
Seedling Rimu on Ulva Island
Small Rimu trunk showing characteristic white-on-grey blotches and banding (Gymnosperm Database - click for link)
Small Rimu trunk showing characteristic white-on-grey blotches and banding (Gymnosperm Database - click for link)
Characteristically ridged bark on mature Rimu
Characteristically ridged bark on mature Rimu (Courtesy James Shook WikiCommons)
Giant Rimu on the Rakiura Track east of Lee Bay
Giant Rimu on the Rakiura Track east of Lee Bay

Halls Totara (Podocarpus cunninghamii)

Also called Mountain or Thin Bark Totara. Maori: totara-kiri-kotukutuku

 

Robust up to 20 m tall. Trunk stout, 1-1.5m diameter clad in papery, thin, freely flaking reddish-grey bark.

Thin Bark Totara and lichens on Ulva Island (part of the Stewart/Rakiura Islands)
Thin Bark Totara and lichens on Ulva Island (part of the Stewart/Rakiura Islands)
Sharply pointed (pungent) foliage of the Mountain Totara (Podocarpus cunningha89 WikiCommons)
Sharply pointed (pungent) foliage of the Mountain Totara (Podocarpus cunninghamii) (89 WikiCommons)

Totara (podocarpus totara)

Totara trunk and bark in forest at Casacade/Kauri Track near Waitakere, Auckland.
Totara trunk and bark in forest at Casacade/Kauri Track near Waitakere, Auckland.
Young Totara (podocarpus totara) Auckland Domain.
Young Totara (podocarpus totara) Auckland Domain.

Bog Pine Halocarpus bidwillii

Etymology: Halocarpus from Greek hals 'sea', 'salty' and karpos 'fruit'

 

A spreading or erect, closely branching shrub, or occasionally a small tree up to 3.5 m tall, with a short trunk up to 38 cm in diameter.

 

A scrubby pine with erect foliage and distinctive white fruit above the seed.

Yellow Pine Halocarpus biformis

Lepidothamnus laxifolius (soft-leaved)

Small tree up to 10 m tall. Likes rich soil.

Pygmy Pine (Lepidothamnus laxifolius)

Lepidothamnus laxifolius (soft-leaved)

 

A prostrate or semi-erect mini-pine found in mountain areas.

Yellow silver Pine (Lepidothamnus intermedius)

Small, straight tree up to 15 m with spreading branches. Bark brown-grey, shed in small platelets, under which the new bark is red-brown.

 

Relatively widespread and common tree of lowland forests. Locally dominant in swamp forests. Also found in boggy areas in shrubland or grassland.

Manoao Silver Pine

Widespread. Up to 20m tall. Slow growing.

 

Lowland to montane. Typically associated with older, poorly drained surfaces with leached infertile soils, and in acid swamps and peats, notably the pakihi lands of western South Island.

Manoao colensoi, or manoao, foliage at Nga Manu Wildlife Reserve, Waikanae (Courtesy Rudolp
Manoao colensoi, or manoao, foliage at Nga Manu Wildlife Reserve, Waikanae (Courtesy Rudolph89 WikiCommons)
Pakihi wetlands at the mouth of the Wanganui River in Westland
Pakihi wetlands at the mouth of the Wanganui River in Westland (Courtesy Te Ara)