Hi Pieter and Ken, Marloth, the South African botanist, carried out various experiments on Gethyllis early in the 20th century. One of the things that he showed was that their flowering may be fleeting, but it does not impact their ability to cross-pollinate, as flowers in the same vicinity emerge at the same time as each other. However, as far as I know, he did not show why this was so and I don't know of any subsequent proof. Best regards, David Victor