monkey-puzzle tree, evergreen tree (Araucaria araucana) native to Chile and widely cultivated elsewhere as an ornamental. The symmetrical branches have an unusual angularity and are completely covered by the stiff, overlapping leaves. The monkey-puzzle tree and related species—e.g., the Norfolk Island pine (A. excelsa) and the bunya-bunya (A. bidwillii)—are all good timber trees. The edible seeds of the bunya-bunya are highly popular in its native Australia. Species of Araucaria form the dominant vegetation of the coniferous forests of Chile and S Brazil. The related kauri pine (Agathis australis) of New Zealand is one of the largest commercial trees in the world, sometimes reaching 200 ft (61 m) in height. It yields good timber and the valuable kauri copal (often called Kauri gum), which was collected in fossil or semifossil form. Other species of Agathis produce similar copals. The genera Agathis and Araucaria together comprise the araucaria family. Although now restricted to the temperate regions of South America and of Australia and the neighboring Pacific islands, fossils—e.g., in the Petrified Forest of Arizona—indicate that the group was once abundant in the Northern Hemisphere. The monkey-puzzle tree is classified in the division Pinophyta, class Pinopsida, order Coniferales, family Araucariaceae.

crossword puzzle, word game in which words corresponding to numbered clues are put into a grid of horizontal and vertical squares to form intersecting words. The puzzle is solved when a player supplies all of the words correctly. Though a type of crossword puzzle has been found inscribed on an ancient tomb in Egypt, journalist Arthur Wynne is generally credited with its invention in 1913. Crossword puzzles became popular with Simon and Schuster's 1924 publication of a crossword puzzle book and now appear in virtually all newspapers. Players vie for titles at various crossword competitions. Reference dictionaries are published to aid players with solutions. See acrostic; anagram.

Evergreen ornamental and timber conifer (Araucaria araucana) of the family Araucariaceae, native to the Andes Mountains of South America. The tree may grow to 150 ft (45 m) in height and 5 ft (1.5 m) in diameter. The rigid, overlapping, needle-pointed leaves are spirally arranged on stiff branches, which form a tangled, prickly network that discourages animals from climbing the tree. The Norfolk Island pine is a relative.

Learn more about monkey puzzle tree with a free trial on Britannica.com.

Puzzle in which words are filled into a pattern of numbered squares in answer to correspondingly numbered clues and in such a way that words can be read across and down. The first crosswords, intended primarily for children, appeared in England in the 19th century. In the U.S., the puzzle developed into a popular adult pastime. By 1923, crosswords were being published in most of the leading U.S. newspapers, and the craze soon reached England. Today crosswords in various forms are found in almost every country and language.

Learn more about crossword puzzle with a free trial on Britannica.com.