When you think of wattlebossoms what colour comes to mind? Yellow?
It is true that most Wattle flowers are of varying shades of yellow (grading down to white and up to orange) but a handful have flowers of a different colour. Botanists working on wattles from other regions of the world can only identify about five that are not yellow. The bright red flowered Acacia reniformis is found in central Mexico, and Acacia previllei with scarlet rods and Acacia sakalava with scarlet balls are found in Madagascar. There are two white with a tinge of pink ones: Acacia arenariaare in Tanzania, and Acacia ogadensis in Ethiopia. In Australia, the Queensland Acacia purpureopetala was discovered in 1904 with mauve pink flowers. Also, the odd purple flower is sometimes found on bushes of the common desert species Acacia tetragonophylla, Kurura. But a big surprise came in 1994 when a group of bushwalkers made a chance finding near Melbourne of a red wattle in flower. It is now called Acacia leprosa 'Scarlet Blaze' and has been grown from cutting successfully at the Royal Botanic Gardens Melbourne. The parent plant died, but the plants grown at the Botanic Gardens will continue to blaze.
In close up the colour of this wattle is due to the red stamens. Botanists believe the red colouring is a result of anthocyanin, a water soluble pigment in the stamens. They think that anthocyanin production in acacias can be switched on or off. What switched this wattle's red lights on?
Wattles can also have other red parts - fresh red stems, and the amazing shaved red barks of the Minnie Ritchie wattles such as Acacia cyperophylla, Acacia rhodophloia, Acacia trachycarpa, and about 20 more species.
Wattle you know wattle you do?
- What's anthocyanin and why does a plant make it?
- Red wattles - visit www.anbg.gov.au/federation-flora/vic-scarlet-blaze/index.html
- Interview a scientist and a horticulturist about a Red wattle, what's special about this?