"Pollination is by bees. It is a complex process.
The 5 stamens and 2 stigmas in each flower are fused to form a single structure, called "Gynostegium."
The pollen grains in each anther are enclosed in a sac called "Pollinium". There are 5 pairs of pollinia per flower. Each pair of pollinia is connected to a sticky disc.
As the bees crawl around the gynostegium, the discs get attached to their legs. In the next flower visit, the pollinia are transferred."
The above information via email:
Kanchi N. Gandhi, Ph.D.
Harvard University Herbaria
22 Divinity Ave
Cambridge, MA 02138
This specimen was approximately 7 feet tall. Leaves slightly pubescent and fleshy.