Thursday 31 January 2008

Saltbush spectrum

Fragrant saltbush (Rhagodia parabolica) is rare in Victoria but you might not think that as you begin the Lerderderg Gorge walk at Mackenzie's Flat. There, saltbush forms dense stands on either side of the track.

The leaves and flowers are discreet and understated in two-tone grey-green but the fruit are as colourful as a bag of parrots. Rhagodia parabolica produces berries in a range of shades from white through yellow and orange to bright red.



At this time of year, silvereyes (Zosterops lateralis) stuff themselves silly on the fruit. They prefer red over other colours, apparently, but neither they nor the other frugivorous species appear reluctant to diversify. I can see their point. The berries all look delicious to me.

Seeds from different coloured fruits exhibit different germination characteristics. Plants pop up from red seed much more rapidly than they do from yellow. White seed has the greatest germination rate after emerging from the back end of a silvereye. (You can think it, but don't say it.)

This array all occurred a 50 metre stretch of the track.