Unlike our European counterparts, here in the United Kingdom we rarely afford the lime tree the esteem it deserves. But it’s not too late to change the record.  

LIME woods once covered a significant area of the British Isles. But despite a long association with its two classically native species, we rarely afford the Tilia genus the esteem it is given by our continental cousins, and especially the Germans.

Germanic love of lime trees is encapsulated in one of the most iconic and celebrated thoroughfares of Europe ‘Unter den Linden’ [Under the Lime trees] in Berlin, named after the trees which line it. Tilia’s British provenance and multi-millennial presence is not in dispute, and neither is the frequency and ubiquity of lime woods in Britain. So, perhaps we should proclaim a strong bond between these British Isles and lime trees.

READ MORE: Hawthorn (Crataegus): Looking at the heritage of two native trees in the UK

Tilia cordata (small-leaved lime or little-leaf linden) is almost certainly native to the British Isles. And so on balance is Tilia platyphyllos (large-leaved or broad-leaved lime).

These two native species were complemented down the centuries with other Tilia species native to continental Europe and western Asia – such as silver-leaf lime (Tilia tomentosa) and Caucasian lime (Tilia euchlora) – and others from places even further afield like North America.

However, the most important addition to our Tilia collection was actually created in Britain, rather than arriving through natural transfer from Europe thousands of years ago or being introduced much more recently by man. The lime tree in the spotlight is a hybrid species, resulting from genetic crossing of Britain’s two native species of the genus Tilia, which undertakes and undergoes inter-specific hybridisation without reservation.

Forestry Journal: Newly-emerged lime leaves will hang downwards at first to protect the tender foliage from spring frosts. Red bud scales still attached and highly visible. Newly-emerged lime leaves will hang downwards at first to protect the tender foliage from spring frosts. Red bud scales still attached and highly visible.

Almost all the large, named and famous lindens (limes) in continental Europe are T. cordata or of T. platyphyllos, but as usual Britain is the exception to the European rule. And so it is with lime trees, which most frequently arise from multiple genetic crossing between our two native species (T. cordata and T. platyphyllos). 

Our contemporary common name for Tilia is ‘lime’, thought to be derived from the Anglo Saxon ‘linde’, ‘linne’ or ‘line’ with linguistic roots in the German ‘lind’. However, the word lime also means ‘sticky substance’ and is used to describe the sticky material (bird-lime) spread on branches in many parts of the world to trap perching birds. Bird-lime is actually a latex sourced from particular types of tree, but there is no evidence to suggest one of these was Tilia. A long shot perhaps, but lime trees in general are attractive to aphids. Aphids reproduce to form huge colonies of sucking insects, which excrete masses of sticky honey-dew, covering the foliage in no time at all. Could this be the origin of ‘lime’ as the vernacular for Tilia?


Intricate tables comparing the number of scales on the winter buds, length of leaf lamina (blade), hairiness of leaf blades, petioles (stalks) and first-year twigs, number of flowers and fruit structure have been used to differentiate the two native species and when they form the hybrid. Britain’s hybrid lime population is broadly based and displays differences for the various characters depending on relative amounts of genetic material from the respective species.

Forestry Journal: Berlin's Unter den LindenBerlin's Unter den Linden

Tilia platyphyllos (large-leaved lime) has larger leaves and generally bigger and more robust plant parts than T. cordata (small-leaved lime). Leaves are longer, wider and downy. There are more hanging flowers per cluster (cyme) and the globular fruits are larger, woody and more prominently ribbed. Despite the respective common names based on leaf size, taxonomists will tell you that using differences in leaf dimensions as a stand-alone factor is not a satisfactory way of distinguishing T. platyphyllos from T. cordata.

The common lime hybrid Tilia x europaea will display phenotypic characteristics intermediate between the parent species depending on the exact genetic makeup of the hybrid tree under scrutiny. T. x europaea is very much Britain’s own lime tree. Trees can grow up to 40 metres or more in height, which makes common lime the tallest non-coniferous tree in the United Kingdom. Tilia x europea is relatively fast growing especially after the first 60 years, easily attaining a bole diameter of 2 m at breast height and maximum height of 40 m within 150 years.

The tree’s exceptional vigour is essentially down to the combined genetic and phenotypic phenomenon known as heterosis and also called hybrid vigour. Heterosis is the increase in plant characteristics, including size and dimensions, growth rate, fertility, and yield of a hybrid organism over those of its parents. Plant breeders exploit heterosis by mating two different pure-bred lines having specific desirable traits, although in this instance nature did the job for them, with hybridisation happening spontaneously in the wider environment.

Forestry Journal: Globular lime fruits in late August and almost ripe and ready for dispersal. Winged bracteoles still attached to assist wind-dispersal of the fruits.Globular lime fruits in late August and almost ripe and ready for dispersal. Winged bracteoles still attached to assist wind-dispersal of the fruits.

Lime cannot match English oak, English yew or even sweet chestnut for longevity but with the right environment and care a lime tree can clock up half a millennium. Edward Step said lime is one of the longer-lived British trees with full life span of 500 years. He noted how those standing in St James’ Park (London) circa 1900 were planted in the 1600s at the suggestion of John Evelyn, the so-called ‘Father of English Forestry’.

Ascending branches of the common lime tree will typically form a tall, rounded crown while the lower branches arch downwards only to turn up again near their ends. The bark is grey and smooth at first but later developing superficial vertical fissures and irregular ‘bosses’, which are raised areas (knots) on the tree trunk (bole).

Terminal branches (twigs) are slender and sleek like those of the beech, staying green or becoming red tinged. Twigs form a zigzag pattern because the terminal bud is always suppressed. They present a flat ‘spray-like’ formation and bear winter buds, which are blunt, flattened and distinctly red in colour. 

The abundance of blush-pink bud scales scattered under the tree during bud burst in April seems remarkable given that only two bud scales were visible all through winter, although there were obviously many more hidden beneath. Leaf buds swell and burst in April releasing cheery bright green new leaves, although Gertrude Clarke Nuttall (1923) described lime in this respect as a real sluggard, a biblical expression for someone or something showing habitual laziness. She describes the leaves as one of the first to go in autumn and last to come in during spring. The leaves burst downwards from the bud to afford the new tender leaves the protection they need from the low temperatures, which may still persist on clear nights during early May. These new, expanding leaves hang vertically like rows of hearts along the branches and as they emerge are folded round the main veins which radiate from the point where the leaf stalk (petiole) is attached.

Leaf expansion continues through May to produce the classic heart-shaped and lop-sided lime leaves, with one basal lobe bigger than the other and sharply-toothed margins, ending at an abruptly sharp distil point. Leaves are a uniformly bright light-green at first, becoming dark green and hairless on the upper (adaxial) surface and paler green with tiny tufts of whitish hairs in the vein axils on the under (abaxial) surface. Leaf stalk (petiole) is typically 3–5 cm long. Leaves of a number of native trees are described as heart-shaped, although the lime leaf is closest of all to a heart shape.
Geometry of the horizontal branches allows fully expanded lime leaves to be arranged so that each and every one ‘fits into’ a pattern, providing good shade while allowing enough light to fall through the canopy. 

Mature pollen is shed from each flower before its female parts mature, thus ensuring cross pollination. Contrary to some reports the T. x europaea hybrid is fertile. The fruits (nutlets) are round to oval in shape, 8 mm in diameter, downy, slightly ribbed and contain several seeds. Trees start to bear fruit at around 30 years old and do so every year thereafter. Seeds germinate into peculiar seedlings, bearing heavily-cut, fingered seed leaves and looking much different from the normal entire, broad leaves that follow on with further growth.

Common lime is one of relatively few trees with a canopy that is equally attractive during full-leaf summer condition and in the leafless winter state. In fact the tree, with its fine branches, graceful branching habit and elevated rounded crown, is the easiest of trees to pick out on the cold winter skyline.

There have been long-standing disputes within the taxonomic fraternity as to whether the genus Tilia should have been assigned to the separate plant family Tiliaceae, as it was until relatively recently, or be submerged in a much bigger plant family called the Malvaceae. Contemporary consensus among taxonomists means Tilia is now assigned to the plant family Malvaceae, which makes Tilia botanically close to some very well-known plants including Gossypium (cotton) and Hibiscus, although at first glance you might not think so.


Despite never having been recorded as a wild woodland tree further north than Cumbria, small-leaved lime can almost certainly claim native status, even though it was one of the last arrivals over the land bridge with Europe. Native status of large-leaved lime is less clear because this tree is calculated to be an even later arrival with a considerably more confined natural distribution in the British Isles. All that said, assigning native or non-native status is a highly subjective exercise depending on the authority ‘in charge’ and what time period it chooses as a cut-off point for the arrival of a tree species.

Today’s restricted distributions of T. cordata and T. platyphyllos belittle the predominant position of lime in Britain’s prehistoric wildwoods as described by Oliver Rackham (1976). In 4,500 bc, says Rackham, ‘lime wildwood province’ covered all of lowland England as far west as Devon and Wales and generally as far north as the Wash, with a narrow band penetrating Lancashire up into the Lake District. Then, as now, T. platyphyllos was always much rarer than T. cordata.

Rackham goes further to suggest that pollen deposit analysts underestimated lime, along with ash, elm and hazel, in prehistoric wildwoods due to relatively low pollen production. Small-leaved lime finds difficulty in establishing from seed and has zero ability to form secondary woodland. This explains why the species became increasingly local and rare as the primary lime wildwoods were felled, says Rackham. 

So, having once covered much of the British Isles, why did lime woods disappear and so quickly? H. L. Edlin assigns this to several factors around the lime tree’s vulnerabilities to the predations of man and beast alike. 

Tilia is a relatively soft, light and easily-worked wood, as far as the full range of broadleaf deciduous hardwoods go. As such, it offered an easy target for early civilisations, who could fell the trees and cut the wood with fairly rudimentary tools.

Although the stumps will coppice freely, the highly palatable new spring shoots would have been grazed and eaten by wild herbivores and domesticated livestock during mediaeval times and earlier.

The hybrid common lime of Britain may have been brought to these islands from Europe as an established hybrid tree before 1600, but it is more likely to have arisen by natural hybridisation within these islands. Common lime is widely planted throughout the UK in parks, gardens and along suburban roads and city streets, and it will tolerate even the most extreme pruning. Lime trees and foliage have always held up well to city smoke, and limes preceded both planes and poplars as the tree of choice for parks and squares in London.

Forestry Journal:  Lime trees have smooth bark at first, which later becomes longitudinally fissured with the formation of irregular raised areas or ‘bosses’ (knots) on the lower part of the tree trunk. Lime trees have smooth bark at first, which later becomes longitudinally fissured with the formation of irregular raised areas or ‘bosses’ (knots) on the lower part of the tree trunk.

Edward Step described lime as a long-suffering good-tempered tree, which, like humans of similar temperament, is subjected to shameful treatment. Why, he asks, should one of our most imposing trees be subjected to such horrible atrocities? The answer lies in the traditional planting of what is essentially a large and tall climax forest tree, with potential canopy height of 40 m and trunk diameter and girth of 2.5 m and 5 m, within inappropriate urban and suburban situations. Common lime is not common as a hedgerow tree, but provides positives for the hedgerow. Not only does this potentially large tree become an excellent hedgerow tree in its own right, but the propensity of epicormic growth low down on the trunk (bole) forms an integral part of the actual hedge. In addition, the numbers of insect species attracted to and supported by lime, including pollinating insects like bees attracted by the nectar-rich flowers, makes common lime a highly useful but still under-rated and under-used species for hedgerow tree planting. Tilia is among the tree species apparently favoured as a living support structure for the growth of semi-parasitic mistletoe. 

Common lime trees grow rapidly but disappear with the same speed because the non-durable lime wood decays and disintegrates quickly once the tree has died or been felled.

Within a matter of months fallen or felled trees left in situ are rapidly covered with sporulation structures of basidiomycete bracket fungi. Weakness in this respect can be gauged on dead, still standing specimens where lime wood with the ‘weakness’ of balsa wood can literally be broken away from the lower trunk by hand.