Little-leaf Linden

Tilia cordata is a deciduous tree growing to 20–40 m (66–131 ft) tall, diameter one-third to one-half the height, with a trunk up to 1 m (3 ft) diameter. The largest known trunk circumference was a specimen in Närke, Sweden, that measured 8.35 m (27.4 ft) circumference at chest height. Some lime trees in Germany are said to be over 1000 years old. The bark is smooth and grayish when young, and firm with vertical ridges and horizontal fissures when older. The crown is rounded in a formal oval to pyramidal shape. Branching is upright and increases in density with age. The leaves are alternately arranged, rounded to triangular-ovate, 3–8 cm (1.2–3.1 in) long and broad, mostly hairless (unlike the related Tilia platyphyllos) except for small tufts of brown hair in the leaf vein axils – the leaves are distinctively heart-shaped. The buds are alternate, pointed egg-shaped, and have red scales. It has no terminal bud. The small, yellow-green, hermaphrodite flowers are produced in clusters of five to 11 in early summer with a leafy yellow-green subtending bract, and have a rich, heavy scent; the trees are much visited by bees, the erect flowers of which being held above the bract. The flower arrangements of T. cordata are distinct from those of the common lime (Tilia × europaea), where the flowers are held beneath the bract. …

The trees favour loamy soil sites, but can also be found on sandy, infertile soils and are not thought to be drought resistant. Dormant shoots of T. cordata can resist winter frost temperatures as low as −34 °C (−29 °F).

In Britain, T. cordata, traditionally called pry, is considered an indicator of ancient woodland and is becoming increasingly rare. Owing to its rarity, a number of woods have been given SSSI status. Cocklode Wood, part of the Bardney Limewoods in Lincolnshire, is the best surviving spread of medieval small-leaved limes in England. A similar site is Shrawley Wood in Worcestershire. Small-leaved lime was once regarded as holy and good for carving. Trees in northern England were found to have established when the climate was warmer and have adapted to the cooling climate. Paleobotanical analysis of tree pollen preserved in peat deposits demonstrates that T. cordata was present as a woodland tree in the southern Lake District c. 3100 BC. In spite of the late migration of T. cordata into the Lake District, pollen diagrams from many sites show rapid expansion, so that within a few centuries, it had become plentiful and even locally dominant in the southern valleys. Maximum values for Tilia from all pollen diagrams available for the north of England show a conspicuous concentration of high values in the southern Lake District. …

Tilia cordata is widely grown as an ornamental tree. It was much planted to form avenues in 17th- and early 18th-century landscape planning. A famous example is Unter den Linden in Berlin. It is also widely cultivated in North America as a substitute for the native Tilia americana (American linden or basswood) which has a larger leaf, coarser in texture; there, it has been renamed "little-leaf linden". It is popular as a shade tree with its dense canopy, as an ornamental tree with its architectural shape, and as a street tree. In the US, T. cordata has been planted in Wellesley, Massachusettes; Modesto, California; Chicago, Illinois; Indianapolis, Indiana; and Atlanta, Georgia as street trees. Europe has espaliered trees owing to their ability to survive heavy pruning. T. cordata is an easy tree to train for bonsai when the training is not done all at once. Letting the tree recoup in between sessions over a period of several months creates a healthy, good-looking miniature tree. Prior to the advent of firearms, it was also commonly used for making shields (as referenced in Beowulf). Tilia cordata survives best in a soil pH range of 5.0 to 8.0. and in USDA hardiness zones 3–7. The tree prefers moist, well-drained soil, and can survive flooding; it is not highly drought tolerant. It does not do well in soils with high salinity.

Notable trees. …

Tilia cordata is the national tree of the Czech Republic and the Slovak Republic, and one of two national trees in Latvia. The leaf of Tilia cordata is also considered a national symbol of Slovenia.