Quercus robur Purpurascens - English Oak

Quercus robur 'Purpurescens' (synonym sanguinea) is a very beautiful cultivar of the Pedunculate Oak, with purple foliage and young branches. Extremely colourful, its foliage is traversed by light and takes on very rich shades of red, brown, and violet. Its young leaves, strongly tinted with red-purple at budbreak, gradually turn brown before turning greenish-purple in summer. This large contrasting tree will find its place in a large garden. It is perfectly adapted to most of our temperate regions. It only requires light, slightly chalky, fertile, and moist soil to thrive.

The Pedunculate Oak, also known as the English oak, male oak, or gravelin, belongs to the Fagaceae family. It is native to a large part of temperate Europe. It thrives in sub-oceanic to oceanic climates, or relatively humid continental climates without excesses. In its natural environment, it can reach a height of 50 m (164 ft) with a spread of 25 m to 30 m (82 ft to 98.4 ft), while its trunk can measure up to 2 m (6.6 ft) in diameter. With a quite exceptional longevity, this oak can live up to 2000 years according to some estimates.

The 'Purpurascens' cultivar will reach an average maturity of 15 m (49.2 ft) in all directions. The growth of this oak is moderately fast. Its habit is generally rounded. The trunk is quite short and is covered with a thick and deeply fissured grey and dark bark. Its young branches are glabrous and shiny, of a purple colour. The late deciduous foliage is composed of alternate, soft, obovate leaves that can reach 5 cm to 15 cm (2 in to 5.9 in) in length and 3 cm to 8 cm (1.2 in to 3.1 in) in width. Each leaf is divided into 5 to 7 pairs of asymmetrical rounded lobes, separated by relatively deep sinuses. The base of the lamina is narrow and has 2 small lobes. The colour of the lamina evolves from red to reddish-brown, then to greenish-purple, with the lower surface being paler. The leaves become brown, quite late in autumn, and remain somewhat attached to the branches before falling. The flowering of this oak occurs in April-May, shortly after the appearance of the foliage, on the annual shoots. The female flowers, yellow-green in colour, are placed in a cupule carried by a long peduncle: this distinctive characteristic is the origin of the species name, pedunculata. The male inflorescences are elongated, pendant catkins, tinged with yellow. They are produced on older branches. The female flowers give way to ovoid and elongated acorns, 1.5 cm to 3 cm (0.6 in to 1.2 in) long. They are often grouped in pairs or threes and attached to a long peduncle. A cupule covered with scales covers one-third of the acorn. The colour evolves from green to brown at maturity, in September and October. The root system of this tree is deep and powerful, both taproot and widely spreading, ensuring a solid and durable anchorage in deep and compact soils.

'Purpurascens', a contrasting tree, will become one of the masterpieces of a natural or even contemporary garden large enough to accommodate it. In spring, a graceful ballet of red to purple young leaves takes place, turning while they unfold from brown to greenish-purple, a shade to be associated with the golden foliage of the 'Concordia' variety, golden honey locust (Gleditsia triacanthos 'Sunburst'), the silver of the white willow (Salix alba) and the white poplar (Populus alba 'Nivea'), as well as the blue flowers of Sophora davidii or arborescent ceanothus. It can be planted either in isolation or in alignment. It also has the advantage of providing pleasant shade, which reflects light in winter, and producing abundant compost, which is favourable to the growth of certain plants that germinate under its cover. Its fruits, sometimes produced in abundance, nourish small animals such as squirrels and jays.