Tilia cordata Swedish Upright - Small-leaved Lime

Tilia cordata 'Swedish Upright' is a very rare variety of Small-leaved Lime tree, brought from Sweden in 1906 by Alfred Rehder to the Arnold Arboretum at Harvard. It forms a medium-sized, remarkably slender, elongated, slim, and narrow tree, reaching a height of 12 to 16 m and a width of 6 to 9 m at maturity, with a trunk with beautiful grey, channelled bark. Its lower branches tend to be pendulous, the middle ones are horizontal, while the upper branches are slightly erect. It also displays the characteristics of the species: shiny dark green leaves that turn yellow in autumn, fragrant and nectar-rich flowering, and fruiting. This cultivar is well adapted to smaller spaces where the size of the species is not suitable. It is undemanding in terms of soil as long as it remains moist and it tolerates urban pollution.

Tilia cordata (synonym Tilia parviflora) belongs to the Tiliaceae family and is native to European forests. It is a deciduous species that thrives in partial shade and has a large canopy, capable of reaching over 30 m in height. It is found in hill and mountain zones, growing up to 1500 m in altitude, usually on moist, deep, fertile, acidic to neutral soil. Its longevity is excellent.

The 'Swedish Upright' variety was brought from Sweden by Alfred Rehder to the Arnold Arboretum at Harvard in the United States in 1906, where it has been admired as remarkable and rare, for its slender and narrow shape. In 60 years, it has not exceeded 13 m in height and 6 m in width. Other observed specimens have dimensions more in line with what is known of this form: 16 m tall and 6 to 9 m wide after 40 years. The growth of this tree is quite slow. Its bark, when mature, is grey and channelled. Its entire, alternate leaves, measuring 7 to 12 cm in length, are rounded, heart-shaped at the base, and finely toothed along the edges. The upper surface of the leaf is glossy green, while the lower surface is glaucous green with reddish hairs. The leaves turn golden yellow in autumn and fall quite early in the season. Flowering takes place in early summer, in June-July. Many small white-yellowish flowers are grouped in pendulous corymbs, with 15 to 20 flowers attached to the branches by long petioles. They are remarkably fragrant and attract bees. They are followed by small smooth grey round fruits attached to a wing called a samara.

The 'Swedish Upright' Lime tree can be planted as a specimen tree. It is valued for its ornamental qualities, versatility in cultivation, and ability to adapt well to urban spaces. Its narrow and upright habit is also appreciated where space is limited. It is easy to grow in many regions. Its fragrant early summer flowering is nectar-rich.