How it works
These cactus trivia questions come in four rounds: what makes a cactus a cactus; water, sun and survival; naming and natural history; and cacti and people.
Read the full guide
Four rounds, from spines to cochineal
What makes a cactus a cactus covers the family, the ribs and the barbed spines called glochids. Water, sun and survival explains why the pores stay shut by day. Naming and natural history follows Linnaeus and the botanists after him. Cacti and people runs from cave paintings in Brazil to cochineal.
For a garden club or a desert trip
The pack names and describes; it gives no growing advice. Tap a choice to check it; the reason and the article it was read in appear with the answer.
Tips
- Naming and natural history is the hard round: Linnaeus, a congress in Vienna and millions of years.
Questions and answers
What are some easy cactus trivia questions?
Nearly every wild cactus comes from which part of the world? Which are the most common pollinators of cacti? What is the characteristic feature of most cacti? The answers are the Americas, bees and a leafless, spiny stem.
How much water can a cactus hold?
Water may form up to 90 percent of the total mass of a cactus. A mature saguaro is said to be able to absorb as much as 760 liters, about 200 US gallons, during one rainstorm.
Why do cacti open their pores at night?
To save water. In the photosynthesis known as CAM, the stomata stay closed through the day, and the plant uses carbon dioxide it stored earlier.
How were the answers checked?
Each was read on October 3, 2026 in the English Wikipedia article Cactus, which every question links. The article's counts of species are not asked, because they change with each classification, and no growing advice is given.