Gyrocarpus americanus Jacq.
Jacquin, N.J. von (1763) Selectarum Stirpium Americanarum Historia : 282. Type: Colombia, Cartagena, N. Jacquin. Holo: BM. Fide Kubitzki (1969).
Coolamon Tree; Gyro Damson; Helicopter Tree; Shitwood; Twirly Whirly Tree
Width of the leaf blades approximating or exceeding the length. Leaf blades about 7-24 x 4-21 cm. Petioles about 4-19.5 cm long. Hairs normally visible with a lens on the upper surface.
Most flowers male with only occasional hermaphrodite flowers. Male flowers: Flowers very small, about 2-3 mm diam. Tepals triangular, small, about 0.75-1 mm long. Perianth tube about 1 mm long. Anther filaments very hairy, about 1-1.25 mm long, anthers about 1 mm long. Hermaphrodite flowers: Style + stigma about 2 mm long. Style sigmoid. Stigma capitate.
Cotyledons papilionate, about 20-35 x 40-50 mm, hairy on the upper surface, 3-5 veined. At the tenth leaf stage: leaf blade triangular or cordate, usually with one large lobe or tooth each side of the midrib, hairy on the upper surface, densely hairy on the undersurface; petiole hairy; taproot and stem swollen, carrot-like (Daucus carota). Seed germination time 3 to 232 days.
Three subspecies occur in the region, see Flora of Australia Vol. 2.
This species may have medicinal properties. This plant used medicinally by Aborigines. Cribb (1981).