Maple

• 1. Introduction

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  Maple trees have been spinning seeds through the air for roughly 60 million years. Those seeds, known as samaras, are shaped to rotate as they fall, carrying a single nutlet on a papery wing far from the parent tree. During World War II, the US Army found that design so effective they built an airdrop supply carrier based on it, capable of carrying up to 65 lb of equipment. That is the kind of quiet influence maple has exerted across human history. The genus Acer contains approximately 132 species, and its reach stretches from the forests of East Asia to the coat of arms of Canada, from violin necks to bowling alley lanes, from Tennessee whiskey to the autumn hillsides of Kyoto. This documentary asks how a single genus of trees became so deeply woven into the material and cultural fabric of so much of the world.

• 2. Sixty Million Years

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  The oldest known fossils of Acer date to the late Paleocene of Northeast Asia and northern North America, placing the genus at around 60 million years of age. Its closest living relative is Dipteronia, a small east Asian genus with only two surviving species today, though Dipteronia's own fossil record stretches back to the middle Paleocene of North America. Maple reached Europe later. The oldest European Acer fossils come from Svalbard, dating to the late Eocene Priabonian stage, roughly 38-34 million years ago. Molecular studies drawing on DNA sequence data from both chloroplast and nuclear genomes suggest that after the genus appeared in the northeastern Palearctic, rapid lineage divergence was followed by several independent dispersals westward and eastward. Today, 54 species of maples meet the International Union for Conservation of Nature criteria for being under threat of extinction in their native habitat, a figure that sits uneasily against that deep evolutionary history.

• 3. Form and Function

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  Most maples grow to heights of 10-45 meters, though others remain shrubs under 10 meters with multiple small trunks rising near ground level. The palmate leaf, with 3 to 9 veins each leading to a lobe, is the form most people recognize, but the genus is more varied than that image suggests. Acer negundo, the box-elder or Manitoba maple, carries pinnately compound leaves that may bear five, seven, or rarely nine leaflets. Several species, including Acer griseum, the paperbark maple, and Acer triflorum, the three-flowered maple, have trifoliate leaves instead. Most maples are deciduous, but a few in southern Asia and the Mediterranean are mostly evergreen. Most are shade-tolerant when young and tend to grow as understory or pioneer species rather than dominant canopy trees. Sugar maple is a notable exception; it can form monodominant forests. The root systems of many species are dense and fibrous enough to inhibit other vegetation from establishing beneath them, and a few, notably Acer cappadocicum, frequently send up root sprouts that can grow into clonal colonies.

• 4. Seeds on the Wind

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  A single maple tree can release hundreds of thousands of samaras at one time. Each samara pairs one seed inside a nutlet with a flattened wing of fibrous, papery tissue, and the two halves detach and spin independently as they descend, buying distance on the wind. The green seeds are typically released in pairs, sometimes still joined at the stem; the yellow seeds fall individually, almost always without the stem attached. Most maple species require stratification to germinate, and some seeds can remain dormant in the soil for several years before sprouting. After flowering, seed maturation takes anywhere from a few weeks to six months. The flowers themselves are small, pentamerous, and appear in racemes, corymbs, or umbels, in shades of green, yellow, orange, or red. Because maple flowers arrive in late winter or early spring, often before many other plants have come into bloom, they serve as an early and commercially important source of pollen and nectar for honeybees.

• 5. Wood, Sound, and Sport

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  Sam Holman, founder of Sam Bat, introduced the maple bat to Major League Baseball in 1998. Today it is the standard maple bat most used by professional players, though maple bats can shatter if they break, unlike ash or hickory. Sugar maple wood, often called hard maple, is the material of choice for bowling pins, bowling alley lanes, pool and snooker cue shafts, and butcher's blocks. Charcoal from maple is also an integral part of the Lincoln County Process used to make Tennessee whiskey. Beyond sport and industry, maple carries a different reputation in music. The back, sides, and neck of most violins, violas, cellos, and double basses are made from maple, and electric guitar necks in maple have been standard since the original Fender Stratocaster and Telecaster, which featured entirely maple one-piece necks. Les Paul wanted an all-maple guitar, but the wood's weight made that impractical; Gibson's Les Paul guitars compromise with carved maple tops, often using quilted or flamed maple. From the 1970s through the 1990s, maple drum kits represented the vast majority of all drum kits made. Some maple wood also carries a naturally occurring figure, known by names such as flame maple, quilt maple, and birdseye maple, that appears randomly in individual trees and often cannot be detected until the wood is sawn.

• 6. Syrup, Pulp, and Paper

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  Quebec is a major producer of maple syrup, an industry worth about 500 million Canadian dollars annually. The syrup comes from sap tapped during the narrow late-winter-to-early-spring window in northeastern North America, when nights remain freezing but days begin to thaw. It takes approximately 40 liters of sugar maple sap to produce a single liter of syrup; the sap travels via tubing to a sugar house where it is boiled down and may also be made into maple sugar or maple taffy. While any Acer species can technically be tapped, most do not carry enough dissolved sugar to be commercially viable. Sugar maple, Acer saccharum, dominates commercial syrup production. Away from the sugar house, maple serves a quieter industrial role as pulpwood. The wood fibers have relatively thick walls that resist collapsing upon drying, giving paper made from maple good bulk and opacity. With a lignin content of approximately 21%, maple is commonly processed into high yield pulp to improve printing properties.

• 7. Leaf Watching and National Symbols

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  In Japan, the custom of viewing maples changing color in autumn is called momijigari, and Nikko and Kyoto are particularly favored destinations for it. In Korea, the same seasonal activity is called danpung-nori, with Seoraksan and Naejang-san mountains among the best-known viewing sites. The sugar maple, Acer saccharum, whose leaves turn brilliant orange, is the primary driver of fall foliage season in northeastern North America. The maple leaf has also carried political weight. It appears on the coat of arms of Canada and on the Canadian flag, where the design is an eleven-point stylization modeled after a sugar maple leaf, which normally bears 23 points. Canada named the maple its national tree, and maple leaf symbols appear in the military rank insignia for Canadian generals. The first attested written use of the English word was in 1260, recorded as "mapole", and it appears again roughly a century later in Geoffrey Chaucer's Canterbury Tales, spelled "mapul". The maple is also a symbol of Hiroshima and appears in the coat of arms of Sammatti, a former municipality of Uusimaa, Finland.

• 8. Pests, Threats, and Collections

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  Infestations of the Asian long-horned beetle, Anoplophora glabripennis, have resulted in the destruction of thousands of maples and other tree species across Illinois, Massachusetts, New Jersey, New York, and Ohio in the United States, as well as Ontario in Canada. The caterpillar of the greenstriped mapleworm, Dryocampa rubicunda, can feed on maple leaves in high enough concentrations to cause temporary defoliation of host trees. Several maple species are susceptible to Verticillium wilt, which can cause significant local mortality; sooty bark disease, caused by Cryptostroma species, can kill trees already weakened by drought. Tar spot, caused by Rhytisma species, commonly disfigures leaves in late summer and autumn but does not usually threaten long-term health. Against that backdrop of threat, dedicated maple collections called aceretums have been established at major gardens worldwide. In England, the five collections at Wakehurst Place Garden, Westonbirt Arboretum, Windsor Great Park, Winkworth Arboretum, and Wisley Garden are notable reference points. The Harvard-owned Arnold Arboretum in Boston holds a particularly significant North American collection. The Esveld Aceretum in Boskoop, Netherlands, is the largest in the world by number of species and cultivars. Acer palmatum alone, the Japanese maple, has over 1,000 cultivars, most selected in Japan, with many no longer propagated or no longer in cultivation in the Western world.