Acacia
'Wattle' day, 1st Sep, was a formerly widely known spring celebration, with a bushwalk and picnic amongst the usually prolifically flowering 'wattle's' the common way to pass the day.
Acacias, or 'wattles' are Australia's national floral emblem and perhaps the largest Australian plant genus. Some species are widely cultivated and of economic or horticultural importance in Australia and overseas.
A couple of sites with Acacia information...
Acacias and entheogenic tryptamines.
Acacia document Jan 2000 version
Aust National Botanic Gardens - Centre for Plant Biodiversity Research