Ephedrine HCL is lab tested, often times more pure and more potent. Ephedra is a shrub that contains the chemical ephedrine. Ephedrine acts as a stimulant similar to methamphetamine.
What you see in stores has guafinessin (lol at my attempt to spell that) in it. It is being sold as a bronchial diolator.
You can still get ephedrine on line. You have to register with the DEA though.