Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Scheme showing the gradual build-up of oil flower/oil bee interactions in two of the World's four regional oil flower systems. The Eurasian Macropis/Lysimachia system and the African/Asian Ctenoplectra/Cucurbitaceae system did not involve switches to hosts outside these plant clades. The latter system, however, involved the repeated acquisition of new cucurbit hosts through time, a finer scale host expansion not shown here.
