Herbs that Tonify Yang

Besides tonifying Kidney yang, what is another important function of Tu Si Zi (cuscutae semen)?

Tu Si Zi tonifies Liver and Kidney to brighten eyes. For dizziness, tinnitus, blurred vision, or spots before the eyes.

Source: Bensky, D. (2004). Chinese Herbal Medicine: Materia Medica. Seattle, WA: Eastland Press. pp. 802. [Q1130]