Thank you for your help on this, Janet. Sadly, I'm still not sure.
I think I'll have to look for this one again this year; maybe get pictures to better show the size. The plant is a creeping type, slow growing ground cover. The bees swarm it when flowering. It's rather small, the smallest of the Desmodium species growing around here; I would guess the leaves do not get any bigger than 3 centimeters, probably more like 2 centimeters long, the flowers are even smaller.
There are other desmodium species growing around here too. Most are unidentified to date.
