Thaumatococcus daniellii is a rhizomatous, perennial herb, up to 3-3.5 m high. The ovate-elliptic leaves (up to 60 cm long and 40 cm wide) arise singly from each node of the rhizome. Thaumatococcus daniellii bears pale purple flowers and a soft fruit containing a few shiny black seeds. The fruit is covered in a fleshy red aril, which is the part that contains thaumatin. When the fleshy part of the fruit is eaten, this molecule binds to the tongue's taste buds, causing sour foods to taste sweet.
Common names for this species include Miracle Fruit (but the unrelated species Synsepalum dulcificum is better known by that name )