Cactus
Saguaros grow in the Sonoran Desert, east and southeast of the Colorado River, and take about 10 years to reach an inch or so in height, and 30 years to reach two feet.  Arms begin forming between 50-100 years in age.  The arms usually grow skyward, but they may droop as a result of frost damage or other factors.

Saguaros bloom at about 55 years of age, their flowers sprouting every year in May.  The blossoms open at night the major pollinators are nectar-feeding bats and stay open about 24 hours. Saguaros can live 150-200 years.

Tarantulas
Contrary to what you've seen in horror movies, tarantulas are not especially dangerous, and the odds of having an encounter with such a critter in the wild are slim unless you go looking for one. Tarantulas spend much of their time in the deep burrows they dig into the earth. They
feed on crickets and other insects, and may eat two or three crickets in a week.  Though they
have frightening fangs, their venom is weak and produces about the same effect as a bee sting.