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.
Each "thumbnail" image below is linked to a larger photograph.
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Araucaria sp. | ||
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Araucaria sp. Note conspicuous female cones at the tips of branches. | ||
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Araucaria sp., monkey puzzle tree. Note large round female cones at the tips of branches. | ||
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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, that is each cone scale with its seed and fused bract falls from the axis of the cone as a dispersal unit. | ||
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Agathis robusta, kauri. Note the size of the tree, the massive trunk, and the upwardly spreading nature of the crown. 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. |
