The purple glory bush or princess flower (Tibouchina urvilleana (de Candolle) Cogniaux) is native to Brazil. Members of the Melastomataceae, Tibouchina are endemic to the American tropics.

The Melastome family contains over two hundred genera with an estimated three to four thousand species spread over the tropics and subtropics worldwide with a single genus (Rhexia) found in temperate zones. Melastome flowers have either four or five petals and stamens either equaling the number of petals or twice the number of petals.

Many Melastomes bear two types of stamens which have two distinct purposes. The short stamens produce pollen lacking genetic material (DNA) as a reward or bee-food. The long, curved stamens produce real pollen for reproduction and only dehisce (release the pollen) when vibrated by the buzz of a visiting bee.

"Here the flowers are usually purple or pink and the pollination anthers are of a similar colour, while the food-anthers are yellow. The pollination anthers are carried on jointed filaments of the on the lower half of the...flower, serving as a support for an insect collecting pollen from the conspicuous food-stamens while being rather inaccessible themselves. Pollen is released by vibration (buzz-pollination...). The flowers are sacrificing some of their pollen to the bees in exchange for pollination....here the allocation of pollen to bee-food is clearly defined." (The Natural History of Pollination, M. Proctor, P. Yeo, and A. Lack, 1996)

The real pollen is carried mostly unnoticed on the underside of the bee to pollinate the next flower. The fake pollen is collected and stored on the bee's hind legs. It will be carried back to the nest.