T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Bog Pine (Halocarpus bidwillii)

Kingdom: Plantae
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Podocarpaceae
Genus: Halocarpus
Species: H. bidwillii
Binomial name: Halocarpus bidwillii
Common name: Bog pine, mountain pine 

Not in Taranaki

This native conifer species is named after John C. Bidwill, alpine plant fancier, who collected in New Zealand in 1839 and 1848. Bog pine is a common spreading or erect bushy shrub of subalpine and alpine areas forming scattered populations on North and South islands. Its range in New Zealand is from Cape Colville on the Coromandel Peninsula, to Stewart Island; usually at 600-1,500 m elevation in the north but coming nearer to sea level in the south. It is a hardy plant, growing in both bogs and dry, stony ground, usually in montane to subalpine scrub.  It is not in Taranaki. McGlone (1980) outlined the history of the vegetation history of Mt Taranaki based on the results of pollen analysis and examination of plant fossils. He found that 18,000 years ago Halocarpus was once growing on the mountain.

As its name suggests, it grows in bogs, but it is just as likely to be found on well-drained, stony ground.  It is 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. Sometimes the horizontal branches form roots as they grow, giving rise to a ring of "shrubs" around the parent. Thus develops an extensive mini forest with the appearance of a huge, low-spreading tree or shrub. The parent tree may die, leaving its circlet of outliers intact and flourishing. Bark is thin, reddish. 
Branches give rise to densely arranged branchlets which are seldom upturned at their tips. Branchlets are covered with small scale-like leaves.
Adult leaves are 1-2 mm long, scale-like, appressed and overlapping on the stem. They have no raised ridge (keel) or hardly so except near thickened leaf tips.
The tips of adult branches often revert to juvenile foliage. Juvenile leaves are 5-10 mm long and 1-1.5 mm wide, spreading all around the stem, stiff but not prickly. The change to adult is abrupt.
Pollen cones - Pollen cones, 3-5 mm in length, are solitary at branchlet tips.
Mature berry-like, seed cone has a white aril surrounding the single 2-3 mm long seed encased in black, leathery skin (the epimatium tissue, derived from the ovule-bearing bract). A fleshy white cup derived from an outgrowth of the epimatium surrounds the base of the seed.

Photo taken at the scientific reserve at "The Wilderness" near Lake Te Anau has excellent examples growing in stony ground.  These trees are slow growing and some in the photos are 200 years old.

 

Mature seed cone with a  white aril