I'm not saying you should click on the parent plant. I'm saying that you should click on the link at the top, which says "View all plants in the genus Dracaena."
http://garden.org/plants/searc...
Another way to do this is to open any Dracaena entry and click on the underlined name of the genus. If you open Dracaena marginata, for instance, you see this:
Dragon Tree (Dracaena reflexa var. angustifolia)
Click on the underlined name of the genus and you'll get these results:
http://garden.org/plants/brows...