The Tree That Lines Korean Roads Has a Cousin That Makes Maple Syrup Acer buergerianum · 중국단풍 / Acer palmatum · 단풍나무

 The Tree That Lines Korean Roads Has a Cousin That Makes Maple Syrup

Acer buergerianum · 중국단풍 / Acer palmatum · 단풍나무

If you have spent time walking along Korean roads or through Korean parks in summer, you have almost certainly stood under one of these trees without knowing its name. They are planted everywhere — along highway medians, in school grounds, beside walking paths, in parking lot islands. And in the hills and temple grounds of Korea, a more graceful relative spreads its layered branches in the dappled shade. Both belong to the same genus. Both turn extraordinary colours in autumn. Most people who pass them daily could not tell you what either one is called.

The roadside tree is Acer buergerianum — 중국단풍, trident maple. The one in the garden and on the hillside is Acer palmatum — 단풍나무, Japanese maple. And both are part of a genus that, on the other side of the world, produces maple syrup — and in Korea, has its own version of that tradition entirely.

 Two Maples, One Genus

The genus Acer contains over 100 species distributed across the temperate Northern Hemisphere. Korea has both native and introduced maple species growing side by side, and the two most commonly encountered in everyday Korean life are easy to tell apart once you know what to look for.

Acer buergerianum, the trident maple, has leaves with three lobes pointing forward — the shape of a three-pronged spear, which is exactly what "trident" refers to. The leaf surface is glossy, the lobes relatively broad and triangular, and the overall leaf size is modest, typically 4–8 cm across. This is the tree planted in rows along Korean urban roads: tough, pollution-tolerant, drought-resistant, and spectacular in autumn when the three-lobed leaves shift from dark green to orange and red. It is native to eastern China and Korea, and was introduced to the West in 1896.

Acer palmatum, the Japanese maple, is a different experience entirely. The leaves have five to seven deeply cut lobes radiating from a central point, giving each leaf a star-like or hand-like profile — palmatum means "hand-shaped" in Latin. The lobes are narrower and more sharply pointed than those of the trident maple, and the overall leaf is more delicate in appearance, with a finely serrated margin along each lobe.

Where the trident maple is a workhorse of urban planting, A. palmatum is a tree of gardens, temple grounds, and hillsides. It grows more slowly, branches more gracefully, and has been cultivated in Korea and Japan for centuries as an ornamental. Hundreds of cultivars exist — purple-leaved, deeply dissected, weeping — but the wild green form remains the most common in Korean nature. In autumn, A. palmatum produces some of the most intense red coloration of any deciduous tree in the Korean landscape, which is why Korean autumn foliage tourism — 단풍 구경 — is organized largely around this species.

 Maple Syrup, and Why Korea Has Its Own Version

Maple syrup is made by tapping the xylem sap of maple trees in late winter and early spring, when freezing nights and warming days create pressure that drives sap through the trunk. The sugar maple (Acer saccharum) of northeastern North America produces sap with a sugar content of around 2–3%, and it takes roughly 40 liters of raw sap to produce one liter of finished syrup. The result is the amber liquid familiar from Canadian breakfasts, with a distinctive caramel depth that comes entirely from the concentration and mild caramelization of the sap's natural sugars.

Acer buergerianum and A. palmatum are both technically capable of producing sap in the same way, but neither has sugar concentrations high enough to make commercial syrup production viable. In Korea, a different maple fills the role that sugar maple plays in Canada: 고로쇠나무 (Acer pictum subsp. mono), the Painted Maple.

고로쇠 sap — 고로쇠물 — is collected in late winter, typically from late January through early March depending on altitude and region. Small holes are drilled into the trunk and tubes inserted; the sap flows clear and very slightly sweet, with the consistency of water rather than syrup. It is not boiled down or concentrated. It is drunk fresh, straight from the collection vessel, sometimes warmed slightly. The experience is nothing like pouring maple syrup on pancakes — it is closer to drinking mineral water with the faintest suggestion of sweetness.

The name 고로쇠 (骨利樹) means "bone-benefiting tree," a reference to the folk belief that the mineral-rich spring sap strengthens bones and joints. Scientific analysis shows the sap contains measurable concentrations of calcium, magnesium, potassium, and manganese — higher than ordinary tap water — giving some grounding to the traditional claim. Annual 고로쇠 festivals are held across Korea's mountain regions — Jirisan, Deogyusan, and Gangwon Province are the main centers — where visitors come specifically to drink fresh sap at collection sites in the forest.

The parallel with North American maple tapping is striking: two different cultures, two different continents, two different maple species, the same instinct to go to the maple tree at the end of winter and take what it offers before the season fully turns.

 How to Tell Them Apart at a Glance

In a Korean park or along a Korean road, the quickest distinction is leaf shape. Three broad lobes pointing forward: A. buergerianum, the roadside tree. Five to seven narrow, deeply cut lobes radiating from a central point: A. palmatum, the garden and hillside tree. Both have opposite leaves — paired across the twig — which is a characteristic of the entire maple genus.

In autumn, both turn. The trident maple tends toward orange and deep red, the color varying by individual tree and soil. The Japanese maple tends toward the most intense crimsons in the Korean landscape, the kind that draws busloads of visitors to Naejangsan and Seoraksan every October. Summer is when you identify them by leaf. Autumn is when you cannot miss them.

Korea walks past these trees every day. The one lining the road and the one gracing the garden are cousins — members of the same genus that, across the world, has taught different cultures to pay attention to what a tree holds in its sap at the turn of the season.

Disclaimer: This post is for educational purposes only. While 고로쇠수액 (sap from Acer pictum subsp. mono) has a long tradition of consumption in Korea, individuals with specific health conditions should consult a healthcare professional before consuming tree sap or any foraged product. Do not tap trees without proper knowledge and authorization. The author is not a licensed botanist or medical professional. Nothing in this post constitutes medical advice.