The Collaborative International Dictionary of English v.0.48:

Jamestown weed \James"town` weed`\ (Bot.)
   The poisonous thorn apple or stramonium (Datura
   stramonium), a rank weed early noticed at Jamestown,
   Virginia. See Datura.
   [1913 Webster]

   Note: This name is often corrupted into jimson, jimpson, and
         gympsum.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Stramonium \Stra*mo"ni*um\, n. [NL.; Cf. F. stramoine.] (Bot.)
   A poisonous plant (Datura Stramonium); stinkweed. See
   Datura, and Jamestown weed.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Atropine \At"ro*pine\, n. [Gr. ? inflexible; hence ? ?, one of
   the three Parc[ae]; 'a priv. + ? to turn.] (Chem.)
   A poisonous, white, crystallizable alkaloid, extracted from
   the Atropa belladonna, or deadly nightshade, and the
   Datura Stramonium, or thorn apple. It is remarkable for its
   power in dilating the pupil of the eye. Called also
   daturine.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Datura stramonium
    n 1: intensely poisonous tall coarse annual tropical weed having
         rank-smelling foliage, large white or violet trumpet-shaped
         flowers and prickly fruits [syn: jimsonweed, jimson
         weed, Jamestown weed, common thorn apple, apple of
         Peru, Datura stramonium]