This evergreen tree is native to Chile and Argentina; its botanical name is Araucaria araucana. Similar in appearance to its relative the Norfolk pine, the monkey puzzle tree has an upright trunk and unusual spidery rope-like branches covered with scaly sharp dark leaves; the branches curve out and sweep upward from the trunk, looking rather like monkey's tails, in fact. However, its colloquial name apparently comes from an English visitor to South America in the 1800s, who thought that monkeys would find climbing the odd tree a puzzle.
I grew up in Victoria, British Columbia, where there are many monkey puzzle trees; hardy to 10°F, they are grown throughout the Pacific Northwest, for they thrive in cool mild climates. Monkey puzzles are slow growers, and take up to 40 years to bear seeds, but in their native habitat, given time, they can reach an impressive 150 feet high. The ones I grew up around reached perhaps 50 feet high and 25 feet in diameter, and were visible for blocks. They are popular ornamental trees in England as well.
Monkey puzzles must have both male and female trees to reproduce. The female plants produce huge prickly cones which take two or three years to mature and contain many large seeds; these cones are apparently edible and form a staple food source for the Pehuenche Indians of Chile. The male plants produce cucumber-shaped dangling cones, not, as far as I can tell, edible.