EuroGraphics Cacti & Succulents 1000-Piece Puzzle. Cactus, or plural "cacti" show many adaptations to conserve water. Most species of cacti have lost true leaves, retaining only spines, which are highly modified leaves. EUROGRAPHICS puzzles are both fun and educational. Puzzle pieces are made from 1.75mm blueboard, and are 100% recyclable, and printed with vegetable-based inks.