Viewing post #800513 by JRsbugs

I think these are hybrids of T. ulmifolia, crossed with other Turnera species, or part of a complex of species included under the umbrella of T. ulmifolia. There's apparently been a lot of research going on in hybridisation of the yellow flowered Turnera.

Turnera is the largest genus in the family Turneraceae.The genus contains 120 species distributed in America and 2 species in Africa (Arbo 2005). Urban (1883) divided the genus into 9 series, Annulares, Anomalae, Capitatae, Leio-carpae, Microphyllae, Papilliferae, Salicifoliae, Stenodic-tyae, and Turnera (=Canaligerae).

The subseries Turnera is composed of 20 species distrib-uted from southern USA to central Argentina (Arbo 1986);

Some artificial interspecific hybrids that resulted from crossing T. grandiflora with other species of the T. ulmifolia complex were studied by Ferna´ndez and Arbo (1993b, 2000b).

http://www.academia.edu/435748...

There's a photo of T. grandiflora on kew which shows the stigma, which I think is being called the crown. It has overlapping petals too, it could be part of the parentage.

http://www.kew.org/science/tro...

A pdf about the breeding systems in the Turnera ulmifolia complex...

Deviation from expected compatibility behaviour occurs in populations of var. angustifolia that have the longest styles

http://labs.eeb.utoronto.ca/ba...