In article , Tim Tyler writes
For instance, I learned that coffee "beans" and chocolate "beans" are not
related to other beans - or to each other - and that chocolate, okra and
durian most likely share their pentagonal symmetry - and other properties -
through a genetic relationship.

These three species are all malvaceous, but not all malvaceous plants
have 5 sepals and petals - several, including Sparrmannia, have 4, and
Octolobus has 8 sepals (no petals). A corolla of 4 or 5 petals is a
trait shared by a large subclade of the eudicots - last I tried I failed
to work out exactly how large - so these three species share a closer
genetic relationship that indicated by the pentagonal symmetry.
--
Stewart Robert Hinsley