Scopolamine is a narcotic that can cause pharmaceutical high.

It can be extracted from the following plants:

Datura stramonium L. (Angel's trumpets, jimson weed )  is weed originally introduced from Europe. Several species this plants are growing wild across much of the United States, including: including Datura wrightii, commonly referred to as the Southwestern Thorn Apple. Datura stramonium is usually called jimson weed; Datura metaloides is colloquially named sacred datura; and Datura inoxia is usually referred to as toloache. The smaller annual, Datura discolor, is often called moon flower.[1]

Duboisia leichhardtii and Duboisia myoporoides are native to Australia.

Side Effects include hot, dry, and flushed skin,  pupil dilation, headache, delirium, rapid and  weak pulse, hallucinations, convulsions, and coma.

[1] http://www.desertusa.com/aug97/du_datura.html