Maples are a type of tree mentioned very nominally in the How to Train Your Dragon Book series.
Maples are types of trees belonging to the Genus Acer and are known for their five-lobed leaves and brilliant fall foliage coloration. Maples occur almost exclusively in the Northern Hemisphere in sub-tropical to sub-arctic climates. They occur in Europe northward into Southern Scandinavia, Asia, Northern Africa, and North America.
The Sugar Maple (Acer saccharum) is native to North America. It is so well-known, that its leaf adorns the Canadian flag. The sugar maple has sap with a very high sugar content. First Native Americans, then later Europeans tapped the trees for the sweet sap and collected to to boil down and create maple syrup. Sap from the red maple (Acer rubrum) and black maple (Acer nigrum) can also be used.
In both the Book series and in real life, the maple tree product - maple syrup - is eaten. In actuality, the maple tree also has many species and cultivars suitable for landscaping and the bonsai hobby. Wood is used for smoking foods, sports items such as baseball bats and bowling pins, weapons such as bows, and decorative wood items. It also carries sound well, so is frequently used to craft musical instruments.
The Hysteric Tribe served a maple product - maple syrup - at their Freya'sday Eve feast in their Great Hall. Hiccup had infiltrated the Great Hall to find the fabled potato and got caught. In order to escape, he fought off Hysterics with their own food, including tipping over "an entire bowl of maple syrup on the floor, sending the Hysterics slipping and sliding all over the place."