Editing Petal (section)

==Corolla==
[[File:Perianth morphology fusion aposepalous apopetalous.png|thumb|Apopetalous corolla|alt=Diagram of apopetalous corolla]]
[[File:2007 brugmansia aurea.jpg|thumb|Tubular-campanulate corolla, bearing long points and emergent from tubular calyx (''[[Brugmansia aurea]]'', Golden Angel's Trumpet, family [[Solanaceae]]).]]
The collection of all petals in a flower is referred to as the corolla. The role of the corolla in plant [[evolution]] has been studied extensively since [[Charles Darwin]] postulated a theory of the origin of elongated corollae and corolla tubes.<ref>{{cite journal|author=L. Anders Nilsson| title=The evolution of flowers with deep corolla tubes |journal=Nature |volume=334 |issue=6178 |pages=147–149 |year=1988 |doi=10.1038/334147a0 |bibcode=1988Natur.334..147N| s2cid=4342356 }}</ref>

A corolla of separate petals, without fusion of individual segments, is ''[[wikt:apopetalous|apopetalous]]''. If the petals are free from one another in the corolla, the plant is ''polypetalous'' or ''choripetalous''; while if the petals are at least partially fused, it is ''gamopetalous'' or ''sympetalous''. In the case of fused tepals, the term is ''syntepalous''. The corolla in some plants forms a tube.