Australian Tropical Rainforest Plants - Online edition
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.
Fruits usually 2-winged, each wing +/- spathulate, about 50-70 x 9-14 mm. Cotyledons much folded. Endosperm scanty.
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.
Occurs in WA, NT, CYP, NEQ, CEQ and southwards to coastal central Queensland. Altitudinal range from near sea level to 900 m. Grows in monsoon forest, dry scrub and open forest. Pantropic, also occurs in Africa, Asia, the Pacific and Central America.
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).