What does "datura" mean?

Datura: A genus of solanaceous plants, with large funnel-shaped flowers and a four-celled, capsular fruit. Note: The commonest species are the thorn apple (D. stramonium), with a prickly capsule (see Illust. of capsule), white flowers and green stem, and D. tatula, with a purplish tinge of the stem and flowers. Both are narcotic and dangerously poisonous.