David answered this on 10-6-2020 during Q & A. David called it Euryales pharax ( sp?). I have been mis-spelling the name and can't find the plant listed in my standard texts. In contrast to herbs for BPH, David said to "astringe the Jing" he uses schisandra and agrimony the most. I did find Euryales Semen, qian shi, Nymphaeacae family, euryale seeds, also called Fox nut, listed in Chinese Herbal Medicine, Materia Medica, 3rd Edition, page 885. I think this is it: the seed "stabilizes the kidneys and secures the essence." I look forward to learning more about the Chinese herbs!