Trees Planet: Populus tremula

Tuesday, February 25, 2014

Populus tremula – Aspen

General Information

Common Name	Aspen
Scientific Name	Populus tremula
Sun Tolerance	Full Sun
Height	10-20 m (33 - 66 ft)
Spread	6 -12 m (20 - 40 ft)
Growth Rate	Fast
Bloom Time	Early Spring
Color	Green
Flower Color	Yellow
Type	Tree
Native	Europe, USA

Classification

Kingdom	Plantae – Plants
Subkingdom	Tracheobionta – Vascular plants
Superdivision	Spermatophyta – Seed plants
Division	Magnoliophyta – Flowering plants
Class	Magnoliopsida – Dicotyledons
Subclass	Dilleniidae
Order/	Salicales
Family	Salicaceae – Willow family
Genus	Populus L. – cottonwood
Species	P. tremula

Populus tremula – Aspen

Populus tremula common name is Aspen also called European Aspen. This is a moderate sized poplar, erect with a lender crown and trunk, is perhaps best known from its roundest leaves which almost ceaselessly quiver and rustle even on calm days. It is very hardy and tolerates well places, unfortunately perhaps, it is often surrounded with numerous suckers which may even form a thicket.

The adult leaves, produced on branches of mature trees, are nearly round, slightly wider than long, 2–8 cm diameter, with a coarsely toothed margin and a laterally flattened petiole 4–8 cm long. The young green shoots soon become smooth and golden brown, and then darken. The branch-less are smooth and shiny with winter buds that are shiny reddish-brown and sometimes somewhat sticky. The roundish leaves, on a long thin much flattened leaf-stalk, are dull, rich green on top, paler yellow underneath, three prominent veins radiate from the base, and the outer rim has indented edges and is sometimes tinged with red. The quivering leaves persist on the tree late into the autumn, turning a rich yellow before they fall.

The male catkins, which open late in February, are woolly on account of the deeply cut and hairy scales, they have purple stamens, later contrasting with the yellow pollen. The seed capsules burst in the latter part of May, but seed rarely germinates well. Propagation is best by root cuttings.

At first the bark is pale greenish-grey and smooth, becoming dark grey and rugged with age. The white wood is light and soft, and is excellent for match sticks and match boxes. Other uses include ‘chip’ baskets, paper pulp and wood wool. The tree seldom reaches a suitable timber size in Europe, so attempts to cultivate it are rare.