Night-blooming cereus

A few night-blooming cereus flowers glow in the beam of a flashlight in this 30-second time exposure taken at Tohono Chul Park in Tucson, Ariz., Wednesday June 30, 2010.

One of Tucson's most unique experiences is happening tonight.

Tohono Chul Park on the northwest side tracks the Queen of the Night mass cactus bloom closely and announced today that they will bloom tonight. 

Tickets are $5, kids 12 and under and members of the park are free.

Tohono Chul will be open from 6 p.m. to midnight. You'll want to wear closed toe shoes and bring a flashlight.

The "Queen of the Night" cactus looks like a dry stick most of the year, but once a year it slowly opens at dusk to a palm-sized flower, which wilts within a few hours of sunrise. About 2,000 people visit the park during its annual bloom nights, according to Tohono Chul.

Find the park at 7366 N. Paseo del Norte, near West Ina Road and North Oracle Road.