A tree reaching well over 100 ft, sometimes 150 ft high; young branches glabrous. Leaves 21⁄2 to 4 in. long, nearly as wide, obliquely heart-shaped at the base, with a short, tapered apex, sharply toothed, dark green and smooth above, pale green beneath, with tufts of hairs in the main axils; stalk slender, 1 to 2 in. long, glabrous. Flowers yellowish white, fragrant, produced in pendent, slender-stalked cymes, 3 or 4 in. long, during early July. Floral bracts 3 to 41⁄2 in. long, 1⁄2 to 7⁄8 in. wide; slightly downy on the midrib at the back. Fruits roundish oval, the shell thick and tough with ribs only faintly showing.
This tree is of uncertain origin, but is now generally believed to be a hybrid between T. cordata and T. platyphyllos, between which it is intermediate. From the former it is obviously distinct in its greater vigour, larger leaves resembling those of T. platyphyllos in size and venation, and the pendulous inflorescence. From T. platyphyllos, to which it is nearer, it differs in the glabrous branchlets, in having the leaves glabrous beneath except for axil-tufts, the more numerous flowers in the inflorescence, and the only faintly ribbed fruits. It is, however, less demanding than T. platyphyllos, growing well on soils too poor and dry for that species. The hybrid has been observed in the wild, but is not common, probably because the difference in flowering time between the two parent species is a bar to crossing, even where they grow together.
T. × europaea is the common lime of the British Isles, and was one of the most popular of all trees for avenues, streets, gardens and parks. It has the objectionable habit of dropping its leaves early, especially in dry summers, and is very subject to attacks by aphides, whose excrement is very sticky, turns black on the leaves rendering them very unsightly in late summer, and drops onto anything below.
Rarely producing fertile seed in economic quantities, the common lime has always been propagated by layering from stools, and the ease with which it could be produced in this way explains its wide use as a tree for formal avenues, where uniformity of growth is essential. Unfortunately, the clone used in Britain for some two centuries has an objectionable propensity to form huge burrs on the trunk, that sprout into dense thickets of succulent shoots, which if not removed ultimately completely hide the trunk.
The common lime reaches to great age, and has the faculty of staying alive for many years after the centre of the trunk has decayed. In consequence, many famous and historical trees and avenues exist. But most of the large limes of Central Europe are T. platyphyllos or T. cordata. The following are some of the largest recorded specimens: Bramshill, Hants, 80 × 211⁄4 ft (1965); Bowood, Wilts, 125 × 14 ft (1975); Welford Park, Berks, 135 × 11 ft (1966); Holme Lacey, Heref., 124 × 213⁄4 ft at 3 ft (1973); Bicton, Devon, 130 × 15 ft (1964); Duncombe Park, Yorks, 150 × 121⁄2 ft and 138 × 121⁄4 ft (1972).
Several gall-producing insects infest the leaves, the commonest being one which produces the curious ‘nail-gall’, a conical, pointed growth on the surface of the leaf, 1⁄4 to 3⁄8 in. long. None of these pests appear to do much permanent damage.
The following clones, long propagated in Holland, are described by H. J. Grootendorst in Dendroflora No. 7 (1970), pp. 74-6:
‘Pallida’. – Of broadly conical habit. Branchlets reddish brown. Leaves yellowish green beneath (T. vulgaris pallida Hort., not T. europaea var. pallida Reichenb., which was a wild form of T. × europaea near to T. cordata). This lime is known in Holland as ‘Koningslinde’ (Royal Lime) and in Germany as ‘Kaiserlinde’. Similar to this, and perhaps a sport of it, is ’ Wratislaviensis’, in which the young leaves are yellow, becoming yellowish green. It was raised at Breslau towards the end of the last century.
‘Zwarte Linde’. – This, the Dutch ‘Black Lime’ has very dark twigs and a broadly ovoid crown rounded at the summit, with almost horizontal lower branches.
For further information on T. × europaea and the two parental species, see Elwes and Henry, Trees of Great Britain and Ireland, Vol. VII (1913), pp. 1656-73; and Miles Hadfield, ‘Notes on Lime Trees in Britain’, Qtly. Journ. For., Vol. 55 (1961), pp. 303-12 and Vol. 56 (1962), pp. 41-8.