Download Nothofagus cunninghamii

Nothofagus cunninghamii
FAMILY: Fagaceae
BOTANICAL NAME: Nothofagus cunninghamii
COMMON NAME: myrtle beech
CONSERVATION SIGNIFICANCE:
None recorded
Greg Jordan
Description
Myrtle beech is a large, spreading evergreen tree up to 40 m tall with a stem diameter
between 150 and 250 cm in favourable environments, but is often a dense understorey
shrub 6–18 m high in wet eucalypt forest and at higher altitudes. The trunk is slightly
buttressed, fluted and often swollen at the base, with adventitious shoots. The outer
bark is brown or deep red to pink, scaly and slightly fibrous and remains attached to
the tree for life.
Myrtle beech has attractive fans of lacy foliage, with new growth that flushes rose
pink to orange-bronze in spring. The leaves are glossy and smooth on both sides, dark
green above but paler beneath, toothed, rounded at the tip and a broad wedge-shape to
triangular at the base, with a prominent midrib and indistinct veins. The leaves have
smallish (6–20 mm) but obvious glandular dots. The leaves are attached to thin
branchlets by short (1 mm long) leaf stalks and alternate along the branchlets in two
ranks (6 to 10 per side). The branchlets are covered in dense, short, rusty hairs.
The flowers are greenish, with separate male and female flowers, on or near the ends
of the branches. The female flowers are located above the male flowers. The male
flowers form catkins (a drooping spike of flowers with no petals) that arise from the
leaf–stem junction. Each catkin is comprised of 1–4 flowers that appear to have no
petals. Each flower is 4 mm wide, has six lobes and holds 6–10 stamens. The female
flowers are in clusters of three and arise from the fork of separate branchlets. They are
surrounded by a leathery, prickly, four-valved ring (involucre) of small leaf-like
structures that are 5–8 mm long, with coarse scales. The two outer female flowers
have a three-keel structure, while the central flower has only two keels. The fruit is
Flora of Tasmania
Nothofagus cunninghamii
nut-like, in threes, and completely enclosed until ripe in the small, prickly, fourvalved involucre. The seeds are narrowly two- or three-winged and 3–4 mm long.
Confusing species
None in Tasmania.
Distribution and Habitat
Distribution of Nothofagus cunninghamii in Tasmania 2004 data.
In Australia, myrtle beech extends from Tasmania to Lake Mountain in Victoria,
where it is largely restricted to cool shaded forests, sheltered valleys and gullies. Its
distribution is closely related to rainfall and humidity, occupying areas where the
mean annual rainfall is between 1000 and 1500 mm, or more. In Tasmania, provided
conditions are moist and sheltered, the trees flourish from sea level on parts of the
west and northwest coasts, to the tree line on mountains at elevations between 100 and
1200 m.
In Tasmania, myrtle beech is a dominant species in cool temperate rainforests
throughout most of the state. Where conditions are right, it also occurs in the
understorey, or as an emergent species in wet forests dominated by species such as
Eucalyptus regnans (giant ash) and Eucalyptus delegatensis (gumtopped stringybark).
At higher altitudes it occurs as a shrub in subalpine and alpine vegetation.
Ecology
Myrtle beech is a slow-growing species that requires cool, shady, moist conditions
and well-drained, fertile soils. Although it prefers shady conditions, it can tolerate full
sun.
Myrtle beech flowers from November to January, with the fruit ripening from March
to May. The highest seed viability occurs in heavy seed crop (mast) years, an event
Flora of Tasmania
Nothofagus cunninghamii
that happens approximately every 2–3 years. At higher altitudes the seed is less
viable.
Myrtle beech can live up to 500 years and has a regeneration cycle that can result in a
forest containing trees ranging from 1 to 500 years old. It does not regenerate readily
after fire but in the absence of fires it will grow as pure stands.
This species is intolerant to phosphorus and highly susceptible to insect and fungal
attack, which damages the timber and often kills the tree. Myrtle beech is particularly
vulnerable to the fungal pathogen Chalara australis, a fatal disease that causes a tree
to become susceptible to attack by the mountain pinhole borer Platypus sp. The fungal
spores of this disease are normally wind-dispersed; however human activity has
elevated the disease incident rates within Nothofagus-dominated cool temperate
rainforest above the natural background levels in undisturbed forest. It appears that
most new sites of infection possibly result from stem and branch wounds caused by
human activities.
Potential for Cultivation
Myrtle beech is easily grown from fresh seed, taking 6–8 weeks to germinate. The
seedlings are very slow-growing and can be difficult to grow on. The seed is orthodox
(will survive dehydration) and has been found to keep no more than a year at room
temperature. Propagation from cuttings has a very low success rate.
The wood is very strong and good for floorings and decking. The timber has many
colour variations, from a pink to reddish to paler brown, and is very hard and strong
with a beautiful, fine grain; features that have made it a prized timber for furniture
making, woodturning and panelling.
Information Sources
Floyd, A.G. (1989) Rainforest Trees of Mainland South-eastern Australia. Inkata
Press, Sydney.
Forestry Tasmania (1995) Tassie's trees. Myrtle Nothofagus cunninghamii. Notesheet.
Forestry Tasmania.
Howard, T.M. (1973) Accelerated tree death in mature Nothofagus cunninghamii
Oerst. forests in Tasmania. Vict. Nat. 90, 343–345.
Milligan, R.H. (1972) A review of beech forest pathology. New Zealand Journal of
Forestry 17, 201–211.
Morley, B.D. & Toelken, H.R. (eds) (1983) Flowering Plants of Australia. Rigby,
Adelaide.
Walsh, N.G. & Entwisle, T.J. (1996) Flora of Victoria. Vol. 3. Inkata Press,
Melbourne.
Flora of Tasmania