There are several species of Indigofera. I grow I. kirilowii. The recemes are pink.

Here is a link that might be useful: images

Thanks, terramadre, you have been most helpful with identifying this plant and helping with my dying poplar tree. I moved in August and am dealing with entirely different plants and different soil. Been gardening 40+ years and never seen the Indigofera. I grew up around poplar trees in NC but had not seen one in 35 years (oops, telling my age). It is wonderful that we all have different fields of expertise when it comes to gardening and I thank you so much for your help.