Datura stramonium

Datura stramonium, known by the common names, jimson weed, ditch weed, stink weed, loco weed,Korean morning glory, Jamestown weed, thorn apple, angel's trumpet, devil's trumpet, devil's snare, devil's seed, mad hatter, crazy tea, malpitte, the Devil's balls, is an erect annual herb, on average 30 to 150 cm (1-5 feet) tall with erect, forking and purple stems. The leaves are large, 7 to 20 cm (3-8 in) long and have irregular teeth
Flowers are trumpet-shaped, white to purple, and 2-7 in long.The fruit are walnut-sized, egg-shaped, and covered in prickles, they split into four chambers, each chamber with dozens of small black seeds
Other websites.
http://www.erowid.org/plants/datura/datura_info5.shtml