Datura grows as a weed in S. California,particiularly in the coastal Santa Barbara region, and was used by the Chumash native peoples there to encourage visions. A friend who grew up in the area tells me local young people in the '60s experimented with it with disasterous effects, including death, due to total ignorance. Extreme care is advised.

The flowers of this plant are wonderful to contemplate. Just communing with the plant (not ingesting it) is metaphysically stimulating.  Seeds come in prickly pods after the flowers are gone. The pods break open and dispense the seeds...so if you're collecting them in the wilde, the optimum time would be just as they start to turn brown/dried-up looking, but before they break open. I am wondering if cllipping the branches and letting the seed "mature" in a brown paper bag (like you do for some herbs) would affect the potency of the seeds. It would certainly make havesting simpler.

Attached: Chumash painting attributed to datura cermonials. "Painted Cave" north of Santa Barbara, CA.