The developmental anatomy of cryptogeal germination in bunya pine (Araucaria bidwillii).
Bunya pine (Araucaria bidwillii) produces large seeds that consist of a massive megagametophyte that surrounds an embryo 25-30 mm long and 3-5 mm in diameter. The seeds germinate on the soil surface, but elongation of the cotyledonary tube pushes the hypocotyl, with its associated plumule and radicle, into the soil (cryptogeal germination). A description is given of the developmental anatomy of germination of seeds freshly collected at Wagga Wagga, New South Wales. Results were compared with those from other studies of bunya pine and from studies of other species of Araucaria.