Araucariaceae family.
Order Araucariales > Family Araucariaceae.
An ancient family often now included under Division Pinyphyta/Coniferae.
Very tall, evergreen trees (or shrubs), columnar or pyramidal in shape with thick trunks.
Parts exude a resinous sap when damaged.
Main branches are horizontal and usually in whorls of 3-7.
Leaves are opposite or spirally arranged on the branches.
Juvenile leaves may be needle-like. Leaves have no stalks.
Mature leaves are broad and flat, or linear and needle-like (awl-shaped).
Mature leaves overlap and are prickly.
There is no distinct midrib and veins are mostly parallel.
Plants can be either male or female or have both male and female cones.
The drooping male cones (strobili) are cylindrical and over 9 cm long.
The microsporophylls, bearing the microsporangia are spirally arranged.
Masses of pollen grains, without wings, are released.
The hard spherical or ovoid female cones are large and erect.
They are on short stalks at the tips of the branches.
The spirally arranged scales (megasporophylls) overlap like tiles.
The bract on the scale can be half fused to it (Aruaucaria) or fully attached.
Each scale has an ovule on the upper surface.
Mature cones are large and heavy and disintegrate to release winged seeds.
Cones have 100 or more bract scales.
There are 3 genera with nearly 40 species.
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- Agathis has about 13 species with 3 in Australia (2 endemic).
Leaves blunt, laterally winged seeds free of the smooth cone scales.
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- Araucaria has 18 species with 1 endemic in Australia.
Leaves pointed, unwinged seeds attached to or enclosed by the cone scale.
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- Wollemia has only 1 species which is endemic in Australia.
Leaves blunt, circumferentially winged seeds free from the spiny cone scales.
J.F.
