Acer rubrum – Red Maple
Acer rubrum, the red maple, is one of the most widespread and striking trees of eastern North America, belonging to the soapberry family (Sapindaceae). It is best known for its fiery scarlet fall foliage and its red flowers that bloom very early in spring, even before the leaves.
Synonyms and Nomenclature
The species was described by Linnaeus (1753). The Kew POWO database recognizes three varieties (var. rubrum, var. trilobum, var. drummondii) and lists numerous synonyms; the most common include:
- Acer coccineum F.Michx.
- Acer sanguineum Spach
- Acer glaucum Marshall
- Acer stenocarpum Britton
- Rufacer rubrum (L.) Small
- Acer rubrum var. trilobum Torr. & A.Gray ex K.Koch
- Acer rubrum var. drummondii (Hook. & Arn. ex Nutt.) Sarg.
In English, the plant is known as "red maple," "swamp maple," "soft maple," and "scarlet maple," while in German it is called "Rot-Ahorn"; the Polish name is klon czerwony. Almost every part of the plant – flowers, petioles, shoots, buds, and fruits – has a red hue, hence the species name rubrum ("red").
Origin and Appearance
The species originates from eastern and central North America – from southeastern Canada to Florida and eastern Texas – where it is one of the most common trees and has the largest continuous range along the Atlantic coast among trees on this continent. It is a medium to large deciduous tree, often 20–30 m tall in the wild, usually shorter in cultivation.
The leaves are opposite, palmate, with 3–5 lobes, serrated, turning deep scarlet and red-orange in autumn – its most famous feature. The flowers are small, red, usually unisexual, clustered in dense bunches, and appear very early in spring, before the leaves develop – one of the first trees to bloom in the season. The fruit is a pair of winged samaras, light brown to bright red, maturing very early, from April to early summer.
Frost Resistance and Cultivation
The red maple is one of the most frost-resistant trees (USDA zones 3–9) – its northern limit reaches the −40°C isotherm, so it easily withstands the harshest Central European winters. It grows best in full sun (where it shows its most beautiful coloration) but tolerates partial shade. It is exceptionally soil-tolerant: it endures wet, swampy sites (even prolonged flooding), yet it is also one of the more drought-tolerant maples; it prefers slightly acidic soil and may develop chlorosis on strongly alkaline soils.
Cultivation from seeds
Red maple seeds mature unusually early – already in late spring or early summer – and fresh seeds are almost non-dormant: when sown immediately, they germinate within a few days to weeks, often in the same summer. Stored, dried seeds acquire slight dormancy and require only a short, cool, moist stratification (about 30–60 days at 1–5°C) before spring sowing. They are sown shallowly in moist substrate. This is an easy tree to grow from seed, with high germination rates and fast-growing, vigorous seedlings.
Care and uses
This is one of the most commonly planted ornamental and avenue trees, valued for its early red flowering and fiery autumn colors; popular cultivars include 'October Glory' and 'Red Sunset'. The wood (known as soft maple) is used in carpentry and veneers, and the tree provides valuable forage and food for wildlife. It is important to remember that wilted leaves are toxic to horses.
Interesting facts
The red maple is one of the most common trees in eastern North America and has the largest continuous range along the Atlantic coast among trees on this continent – today it is much more abundant than before colonization, partly due to fire suppression. It is also one of the first trees to flower each spring, covering itself in red before leaf development; it is the state tree of Rhode Island.
Summary
The red maple is a graceful, extremely frost-hardy tree with fiery autumn colors and early red flowering. Growing it from seed is easy – fresh seeds germinate almost immediately, and stored seeds require only a short cool stratification – making it an excellent choice for cooler climates.
