TLDR  Russelia equisetiformis may help promote hair growth.   
     
We don't know much about this study yet.
We're maintaining the world's largest resposity of hair loss
                research. You can help out the community by 
sending a PDF of this study here
.
Not sure how to get a study's PDF? You can email the authors
                  of the study.
             
           75 citations
,
  October 2002   in “Journal of Dermatological Science”    Sophora flavescens extract may help hair grow by affecting growth factors and blocking a hair-related enzyme.  
     
           37 citations
,
  January 1993   in “Yakugaku zasshi”    Ginkgo biloba leaf extract may help hair regrowth and improve heart health.