I had to think this one through.
I usually do not embroider stems.
Then, I saw some people whom I greatly respect doing the embroidery thing, and I thought I'd try it. I looked into a few choice stitches and decided on the heavy chain stitch. (Link)
The red fabric in this photo was something I impulsively picked up, and for years I wondered how I would ever use it. I decided to use it on the little flowers between the triangles.