Pinophyta (Gymnosperms): Pinophytina. The Araucariaceae are monoecious or dioecious trees comprising two genera and about 30 species of the Southern Hemisphere. The leaves are opposite or spirally arranged and are needlelike to broad. The male or microsporangiate strobili are axillary or terminal, comprising many spirally arranged microsporophylls, each bearing 5-20 linear, pendant microsporangia on the lower surface. The pollen grains lack wings. The female or megasporangiate strobili are generally large and somewhat woody, with numerous spirally disposed ovuliferous scales, each fused with its bract and bearing a single median ovule on the upper surface.


Araucaria cf araucana, monkey puzzle tree. These images appear to represent female and male individuals of the dioecious species commonly called monkey puzzle tree.  1 - Female, note large round female cones at the tips of branches, 2,3 - male, note elongated male cones at the tips of branches.
Araucaria columnaris, Cook pine.
Araucaria columnaris, Cook pine.  Male (microsporangiate) strobilus (left) and microsporophyll (right) with several elongated, pendulous microsporangia.
Araucaria columnaris, Cook pine. Imature female (megasporangiate) cone scale/bract units.  Left: adaxial (upper) view with small (darker) medial scale visible (mostly fused to the much larger subtending bract).  Right: abaxial (lower) view of bract.
Araucaria columnaris, Cook pine. Note the large woody cone and the ovuliferous scale with a single medial seed that is embedded in the scale. Also shown is a seed that has been removed from its scale. In this family the ovuliferous cones disintegrate while still attached to the tree; each cone scale with its seed and fused bract falls from the axis of the cone as a dispersal unit.
aga_rob_mics.jpg (9032 bytes) aga_rob_megs.jpg (10274 bytes)
Agathis robusta, kauri. 1 - Note the size of the tree, the massive trunk, and the upwardly spreading nature of the crown. 2 - The leaves on this species are quite broad and not typical of conifers in general. The spherical megasporangiate cone contains many 1-seeded ovuliferous scales that fall apart at maturity. 3 - Microsporangiate cone (immature).  4 - Megasporangiate cone (immature).

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