Did the leaves have milky latex?  Looks like one of the many genera in the Apocynaceae

It looks like Cestrum elegans of Solanaceae family.

Could its key/descriptive feature be that its leaf arrangement is, tri-foliate with a long leaf stalk?    

I did not notice any latex nor tri-foliolate leaves. All Cestrums seem to have tubular flowers with shorter petals than this one. Any other suggestion ?

Thanks in advance.

Frieda, can you tell please the exact place when was potographed the plant? I´m here  in Michoacan state.

I think could be Rubiaceae, we can see the ovary place, think about it1

Photos were taken in Michoacan, between Angangueo and Tlalpujahua,  19°32'N 100°23'W, near a marsh. Certainly not a Rubiaceae because of the alternate leaves and superior ovary  ... Fresh leaves had a typical odor reminding that of Clerodendron.

Frieda Billiet

The above plant is Cestrum roseum Kunth of the Solanaceae family. The native range of this plant species is Mexico.

https://www.inaturalist.org/taxa/290771-Cestrum-roseum/browse_photos

https://es.wikipedia.org/wiki/Cestrum_roseum

Thanks!