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Monkey Puzzles, Norfolk Island Pine, Kauri, Candelabra Tree.
Vegetative. Evergreen (in some, the leaves remain green for up to fifteen years); trees. Resinous (with resin canals in stem medullary rays and cortex, and in the leaves). Main branches whorled. The leafy branchlets not flattened. Mature leaves broad and flat (often broad-based, with many parallel veins), or linear; acicular, or relatively soft (mostly); not clustered; alternate (although the main branches are usually whorled). Longitudinal resin canals present in the leaves.
Reproductive organization. Monoecious (Agathis, usually), or dioecious (Araucaria). The ovules borne in female cones. The female cones woody (almost spherical). The seed-cone scales spirally arranged; deciduous, the cones disintegrating at maturity (the seed either shed attached to the cone scale, with the latter serving as wings, or detaching from the cone scale along with a wing); woody. The ovules borne proximal-adaxially on the seed-cone scales. The bract-scales extensively fused to the seed-cone scales in mature cones (though in Araucaria the tip is conspicuously free, constituting a “ligule”). The seed-cone scales 1 ovuled. The ovules anatropous.
Male cones elongate, the microsporophylls with 5–15 abaxial pollen-sacs in Agathis, 8–15 in Araucaria. The pollen grains produce numerous prothallial cells. Pollen-sacs 5–15 per microsporophyll. Pollen without air bladders. Pollination anemophilous, with fertilization involving lodgement of the grain on the cone-scale (or in Araucaria on the “ligule”), and growth of the pollen tube to the ovule via a nucellar beak projecting through the micropyle (i.e., no “liquid drop” mechanism).
Seeds and seedlings. Seeds winged. Cotyledons 2(–4).
Wood anatomy. Growth rings indistict. Heartwood present and distinctively coloured (usually, though often weakly developed), or present but not distinctively coloured, or absent (Araucaria cunninghamii). Latewood not conspicuous. Wood without distinct odour; with a distinct taste (Agathis australis), or without distinct taste (usually); not greasy; without dimpled grain. Tracheids with alternate bordered pits; without callitroid pit-border thickenings. Earlywood tracheids without spiral thickenings. Axial parenchyma absent. Ray tracheids absent or very infrequent. Earlywood ray cells with horizontal walls thinner than those of the adjacent vertical tracheids above and below the ray. Latewood ray cells with unpitted horizontal walls. Ray cells without indentures; without nodular thickenings on their end walls. Ray tissue without crystals. Earlywood cross-field pits cupressoid (or araucarioid), or piceoid and cupressoid (Araucaria cunninghamii). Normal vertical resin ducts absent.
Geography, cytology. Temperate to tropical; Southern hemisphere, excluding Africa.
Basic chomosome number, n = 13.
Taxonomy. 40 species; Agathis, Araucaria, Wollemia. Subclass (after Christenhusz et al., 2011): Pinidae; Araucariales.
Comments. Wollemia nobilis was discovered in 1994 in a temperate rainforest wilderness area of the Wollemi National Park in New South Wales. Its closest relatives seem to be Jurassic species of Agathis, and Cretacious fossils represented by the form genus Araucarites and Araucarioxylon (wood).
Miscellaneous. • Auraucaria heterophylla, habit. Araucaria heterophylla at Albany, Western Australia. The characteristic, symmetrical habit is exemplified by the young trees, and also by a tall specimen silhouetted on the horizon. Note the evidence of precise self pruning, belying the traditional description of Araucariaceae as possessing only shoots of unlimited growth. Photo by L.W., 2006. • Araucaria heterophylla, female cone details: Watson (2006). Araucaria heterophylla. A mature female cone in process of disintegrating (left); separated cone scales (right). Each winged cone scale represents consolidation of a one-ovuled ovuliferous scale and its subtending bract. Photo by L.W., 2006. • Agathis and Araucaria: technical details (Sporne). • Cone-scale interpretations of Araucaria spp. (Florin). • Agathis australis, photo: © Zoya Akulova. • Agathis australis: Cheeseman et al., Ill. of N.Z. Flora (1914). • Agathis australis, Araucaria bidwillii, Araucaria heterophylla (Dallimore and Jackson). ARAUCARIACEAE. Araucaria excelsa R.Br. (Norfolk Island Pine) = Araucaria heterophylla (Salisb.) Franco. • Leaf epidermis: Agathis alba (Florin). ARAUCARIACEAE. Abaxial leaf epidermis of Agathis alba, showing stomatal configuration. From Florin (1931 and 1951). • Wood anatomy: Agathis vitiensis. ARAUCARIACEAE, wood. Agathis vitiensis, RLS showing tracheids with alternately arranged bordered pits (Phillips 1948).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2008 onwards. The families of gymnosperms. Version: 5th August 2019. delta-intkey.com’.
