Sugar maple

The leaf on Canada's flag and the sweet syrup

The maple leaf is on Canada's flag! In spring, drill a small hole in the trunk and sweet sap flows out — it is boiled into maple syrup (40 buckets of sap make 1 bucket of syrup). Canadians pour it on pancakes. In autumn maple leaves turn fiery red and yellow — as if the whole forest were on fire. The leaf has 5 'fingers'.

The sugar maple (Acer saccharum) is the key tree of the deciduous forests of eastern North America, 35 m tall and 300–400 years old. In early spring (+5 °C by day, −5 °C at night) starch in the roots turns to sugar and trunk pressure pushes the sap up — sap with 2–3% sucrose is boiled down 40:1. Quebec produces 70% of the world's maple syrup (60,000 tonnes a year); Indigenous peoples (Anishinaabe) taught the method to Europeans. Autumn colour: chlorophyll breaks down, revealing carotenoids (yellow), while anthocyanins (red) are newly made. The hard wood makes bowling lanes, basketball courts and violin backs. The stylised leaf has been on Canada's flag since 1965. Warming is pushing the sap season north.

Fun facts

• 40 buckets of maple sap make just 1 bucket of syrup.
• Basketball courts and bowling lanes are made of maple.
• Quebec produces 70% of the world's maple syrup.