In Spanish something similar happens. The common name here for Aloe vera is "sábila" (sometimes "sávila") and that's how people generally refer to the plant. When they discover there are other species of aloe, they tend to call those sábilas as well (until they use the genus name). In casual conversation the word sábila can mean both things, though in its strictest sense it refers only to the species Aloe vera.
