Tetratheca ciliata is known commonly as Black-eyed Susan or as Pink Bells. Each flower has four dark purple stamens but pollen is not usually found on the outside of these. The anthers have a circular hole at the top and may well operate by buzz-pollination. To operate such flowers, the insect has to produce a sound of a certain frequency and this dislodges the pollen. Bees are likely candidates for such pollination mechanisms but no major pollinator for Pink Bells has been identified.