Canada's flag leaf has 11 points; a real sugar maple leaf has 23
The maple leaf on Canada's flag is a simplified sugar maple leaf with eleven points, less than half the usual 23. Maples inspire engineers too: their spinning winged seeds were the model for a US Army airdrop carrier in the Second World War that could deliver 29 kilograms of supplies.
The genus Acer holds roughly 132 species, most native to East Asia, with others across Europe, North Africa and North America. Only Acer laurinum crosses into the Southern Hemisphere. The oldest maple fossils, about 60 million years old, come from the late Paleocene of north-east Asia and northern North America, and Europe's earliest turn up on Svalbard. Once given a family of their own, maples now sit in the soapberry family, closest to the Chinese genus Dipteronia and more distantly to horse-chestnuts.
Most maples are trees of 10 to 45 metres, though some are multi-stemmed shrubs. Their leaves grow in opposite pairs and are usually palmately lobed, but box-elder has compound leaves with up to nine leaflets and paperbark maple carries three. Many species are deciduous and famed for autumn colour, while a few in southern Asia and the Mediterranean stay mostly evergreen. Sugar maple can dominate whole forests, and dense fibrous roots in many species suppress plants beneath them. Their small green, yellow, orange or red flowers give bees early spring nectar.
The fruit, called a samara, key or helicopter, pairs each seed with a papery wing that spins it away on the wind; one tree can release hundreds of thousands at once, and some seeds lie dormant for years. Threats are real: 54 species meet the international criteria for risk of extinction in the wild, and the Asian long-horned beetle has destroyed thousands of maples in several US states and Ontario.
Canada has ten native species, at least one in every province. The emblem began in Quebec, where the sugar maple matters most, but today stands for maples in general; it appears on the coat of arms, generals' insignia and the Toronto Maple Leafs' name. The English word is old, spelled mapole in 1260 and mapul in Chaucer's Canterbury Tales. Japanese maple alone has over 1,000 cultivars, many selected in Japan, and several species are favourites for bonsai.
Source: Maple
