Acer opalus Seeds | Italian Maple
LATIN NAME: Acer opalus
COMMON NAME: Italian Maple
Plant Profile
Italian maple is a southern European species, found from the Pyrenees through the Apennines into the Balkans, usually on limestone slopes and in mountain woods between 500 and 1700 metres. It grows fifteen to twenty metres tall with a broad, rounded crown and grey bark that cracks into small plates with age.
The leaves are three to five lobed, leathery, dark green above and softly hairy beneath, and they turn a clear yellow in autumn. The flowers appear before the leaves in early spring, in small yellow-green clusters, and the winged seeds ripen in late summer, hanging in pairs.
Old trees often carry several trunks from a low fork, and the crown broadens with age.
Science & Biotechnology
The species has an unusual place in the history of sugar. Sap from Italian maple and its relatives was boiled in parts of southern Europe long before cane sugar was cheap, and comparative studies of sap sugar content across European maples have looked at how the species compares with its North American relatives.
More recently it has been included in studies of drought response in Mediterranean maples, since it grows on thin, dry soils and may hold traits useful for urban planting. Its leaf anatomy, with a thick cuticle and hairy underside, is part of what makes it more heat tolerant than the sycamore maple that often grows nearby.
Its leaf litter breaks down quickly and returns calcium to the soil, which matters on the thin limestone soils it favours.
Uses & Benefits
It is a useful shade tree for a dry garden, tolerant of limestone and summer heat once established, and it makes a good street or park tree in southern Europe. The wood is hard and pale, used locally for tool handles and turnery.
In autumn the yellow foliage is the main ornamental feature, since the spring flowers are small. It is also one of the maples that can be tapped in a small way, though yields are far below those of sugar maple, and the practice survives only as a curiosity in a few Italian villages.
In Italy the tree is often left in field corners for shade, and the fallen leaves are gathered for mulch.
Growing from Seed
Collect seed as soon as the wings turn brown, and sow without drying, since maple seed loses viability quickly. A cold period of eight to twelve weeks improves germination; sow one centimetre deep in a gritty mix and keep at 15C. Seedlings grow steadily and can be planted out after two years.
Give full sun and well-drained soil, and water through the first two summers; after that the tree copes with dry spells better than most maples. It tolerates alkaline ground, which makes it a useful alternative to the usual lime-hating species in a Mediterranean garden.
Our Take
Italian maple is a modest tree by maple standards, and that is part of its appeal: it tolerates heat, lime and drought, and it asks for little beyond a sunny site.
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