Heather and the Calluna are two plants of the same family, but are of a different Kind, even if they resemble each other much.
Sometimes called Heather (a word that means to sweep, a word from which is derived the Heath) as was used to build the scope.
Prefer soils with an acid ph.
The plants marketed under the name ERICA belong to the Family of "Ericaceae" and include 2 Kinds:
THE GENUS ERICA
The Species most commonly used are:
Heather
Erica Darleyensis (Erica x darleyensis): it is a cross between the species Carnea, and Erigena occurred randomly at the end of 1800)
Erica Gracilis
The GENUS CALLUNA (even if it is not a Heather is often called Heather)
The only Species is the:
Calluna Vulgaris (common name Heather)
Data sheet