- Family: Soapberry Family – Sapindaceae
(formerly Maple Family – Aceraceae)
- Growing form and height: Tree. 10–20 m (30–70 ft.).
- Flower: Regular (actinomorphic), yellowish-green, approx. 10 mm (0.4 in.) across. Sepals 5, free, triangular, alternating with petals. Petals 5, free, elliptic. Flowers bi- or unisexual. Receptacle nectar-secreting. Stamens 8. Pistil formed from 2 fused carpels. Inflorescence an approx. 20-flowered corymb.
- Leaves: Opposite, lacking stipules. Blade palmately lobed with 5 to 7 lobes. Points of lobes long-tapered. Stalk approx. 10 cm (4 in.) long, containing latex. Autumn colour varies from deep scarlet to orange and yellow.
- Buds: Broadly egg-shaped, red–green. On the tops of branches in bunches of 3, the middle one bigger than the other two.
- Fruit: Two-winged schizocarp (the parts being samaras).
- Habitat: Broadleaf woods. Also an ornamental, often an escape.
- Flowering time: May–June. Flowers when coming into leaf.
Maples are deciduous or evergreen trees or shrubs. The genus comprises 100–200 species depending on the definition. Most of these occur in the temperate broadleaf forests of the northern hemisphere. The oldest known maple fossils are from the early Cretaceous. In Finland, Norway maple arrived approx. 6,000 years ago from the south-west and south-east.
Norway Maple is a demanding tree especially of dryish broadleaf woods. It does not tolerate swampy ground, and is frost-sensitive in the winter. When young it tolerates shade well, but needs plenty of light when older. The Norway maple flowers just before coming into leaf, and it is both wind- and insect-pollinated. It is a fast-growing species that develops a beautifully dense and rounded crown. It naturalises easily from cultivation because of the excessive seed production.
Maples are commonly grown as ornamentals. Wood is yellowish-white or slightly reddish, and fairly hard. It easy to polish and is therefore valuable e.g. for making musical instruments and furniture.
Sycamore Maple & Box Elder
Acer pseudoplatanus & Acer negundo
In Finland also some other Acer species can be found in parks and sometimes as escapes, at least Sycamore maple (Planetree maple, Great maple) and Box elder (Boxelder maple, Ash-leaved maple, Ash-leaf maple, Maple ash, Manitoba maple). Sycamore maple’s flowers are greenish and hanging in panicles. Box elder is dioecious and its leaves are pinnately compound.