如何在R的ggplot中添加自定义系列标签?

I have a plot (sample code pasted below) that I am trying to add by own labels for the series information. Instead of plotting "p1s1" "p1s2" "p3s4", I would like "treatment 1" "treatment 2" "treatment 3". I have used levels(series_id) to get the unique series names and used a lookup table to get the descriptions. (I think this gets them in the same order they are plotted?) and I have these descriptions in a vector called treatment_descriptions. I have a plot (sample code pasted below) that I