A round-topped tree, already over 100 ft high in Britain, with pendulous branches and a singularly graceful habit; young shoots downy. Leaves roundish ovate, heart-shaped or nearly straight across at the base, mostly oblique, pointed, regularly and sharply toothed, 2 to 41⁄2 in. long, about three-fourths as wide, dark green and slightly downy above, white with a close felt beneath; stalk downy, up to 21⁄2 in. long. Flowers dull white, three to ten together in drooping cymes 2 to 3 in. long. Floral bract as long as the cymes, narrowly obovate, sprinkled with minute tufted down. Fruits globose to orange-shaped, grooved, warty, 1⁄3 in. wide.
A tree of unknown origin. It first came to botanical notice in the descriptive catalogue of the Muskau Arboretum (1864), where it had been received (possibly from Booth of Hamburg) under the erroneous name of T. americana pendula. In renaming it T. tomentosa var. petiolaris, Kirchner confused it with T. petiolaris DC., described from a specimen taken from a tree growing in the Botanic Garden at Odessa. This tree, as it later proved, was simply a form of T. tomentosa with longer-stalked leaves than normal, but Hooker, in the Botanical Magazine, took up the name T. petiolaris for the present tree, by which it has been known ever since. It is doubtful whether ‘Petiolaris’ is anything more than a pendulous form of T. tomentosa, and considered as such could take the name T. tomentosa ‘Pendula’. Its pendulous habit is obviously not a specific character. Neither is the length of the petioles of much significance, since it is barely more than on some wild trees. The wartiness of the fruits, sometimes advanced as a mark of difference from T. tomentosa is in fact normal for that species. We are left with the depressed-globose shape of the fruits, but this might be no more than an outward sign of sterility, for the pendent white lime rarely produces fertile seed.
‘Petiolaris’ was in cultivation in Britain by the 1840s, since Elwes and Henry mention a tree in the University Botanic Garden, Cambridge, planted about 1842. But it appears to have been unknown to Loudon. It is one of the most beautiful of limes, and its fragrance is perceptible many yards away when it flowers in late July and August, at the end of the lime season. Bees find something narcotic in the flowers, as they may be seen in the evenings lying in scores beneath the tree, and many do not recover.
Among the largest specimens of the pendent white lime are: University Parks, Oxford, 102 × 93⁄4 ft (1975); Magdalen Bridge, Oxford, 90 × 113⁄4 ft (1968); Egrove House, Kennington, Oxfords., 100 × 121⁄2 ft (1968); Stratfield Saye, Hants, 107 × 101⁄4 ft (1968); Westonbirt, Glos., in Willesley Drive, 102 × 91⁄2 ft (1976); Botanic Garden, Bath, 108 × 12 ft (1975); Warwick Castle, 98 × 10 ft (1975).
T. ‘Orbicularis’. – A tree to about 80 ft high, with the habit of ‘Petiolaris’, though somewhat more pendulous and with a more conical crown. The leaves have shorter stalks, are very glossy above, and the felt of the undersurface is grey rather than silvery. They remain on the tree until late October. (T. argentea orbicularis Carr.; T. × orbicularis (Carr.) Jouin).
This tree arose in the nursery of Messrs Simon-Louis, near Metz, about 1868. The seed-parent was T. ‘Petiolaris’, and E. Jouin, the tree-nursery manager, considered that the pollen-parent was T. × euchlora, which grew nearby. Two examples were planted at Kew in 1900; they are 72 ft and 82 ft high, 53⁄4 ft in girth (1974).
An illustrated account of this hybrid by Nigel Muir was published in Gard. Chron., Vol. 182 (1977), pp. 28-30.