When you look at the surface of its leaves you see that it's shiny and it also feels sticky. This is due to the exudation of various compounds that the plant produces. These compounds are broadly known as flavonoids, terpenoids, and saponins. 
Growing up the use of plant herbal remedies was a common practice in our household, from preparing Aloe juice with Aloe picked from our backyard, to growing a small mint bush and adding it to rooibos tea. As a child I think I learnt about plants partly through my sense of taste.