This is Datura wrightii. The flowers open when it is fully dark out and close up a couple hours after sunrise. On overcast days they may stay open longer. Daturas are larval host plants for the Pink-spotted Hawkmoth, Five-spotted Hawkmoth, and the Carolina sphinx Moth.This plant is grown as an annual in all USDA Hardiness Zones and is a tender perennial in USDA Hardiness Zones 9 to 11.