Hi Leigh Anne,
Most types of lavender are edible and usable internally and externally but Lavandula angustifolia cultivars are the best for internal use. Others have a variation of essential oils that are less tasty and could be irritating internally.
It will still be great for salve or oil regardless of the species, as long as the aroma is desirable to you. 🙂
With warmth,
Benna