Gumtrees are the quintessential Australian - in about 900 varieties. From the diminutive Varnished Gum of alpine Tasmania to 400-year-old forest giants like the Mountain Ash, eucalypts dominate almost every treed environment from the desert to the sea. Barron Field, a colonial judge, naturalist, intellectual and aristocrat was utterly unimpressed, writing in 1822: "there is not a single scene...of which a painter could make a landscape, without greatly disguising the true character of the trees", which just shows that breeding and education are no inoculation against stupidity.
Carlos Castaneda wrote that his Yaqui mentor, Don Juan, said "Twilight is the crack between the worlds". He was talking about other levels of reality. I don't know about that, but its certainly a time of change and unique effects. With a softness, and sometimes colour, twilight is a wonderful time to make images.