What does the species name 'fistula' mean? _Cassia fistula_ is tree with yellow flowers. As a medical student what amazes me is that the word fistula implies other meanings. A fistula, at least in medical science refers to a tract with two epithelial openings.

The botanic and medical term _fistula_ is directly derived from the latin word _fistula_ meaning tube or pipe.

Both the medical fistula and the fruits of the _Cassia fistula_ tree show phenotypes similar to a tube.

I will spare everyone the medical example picture, but here are the fruit of _Cassia fistula_ , which are sold as "manna":

![You can even eat it!](