Astragalus propinquus (or A. membranaceous), known as huang ch’i, huang qi, or bei qi, is one of the “50 fundamental herbs” of Chinese medicine.
The root of this perennial bush has been shown to stimulate the nervous and immune systems. Studies have demonstrated its ability to increase interferon production and enhance T-cell performance. It is also reputed to strengthen the lungs, adrenal glands, promote healing, and reduce fatigue. It’s even used in Lectranal, which fends off hay fever.
You’ll occasionally see astragalus listed as an aphrodisiac. If you have a look at astragalusroot.net, which (naturally) promotes The Wonders of Astragalus Root, you’ll see that sexual benefits are listed among its wonders. For the most part, it has to do with fixing male issues regarding blood flow, and the rather vague “virility” benefit.
To the best of my knowledge, it has no actual aphrodisiac qualities.