A group of hybrids between H. japonica and H. mollis, originally described by Rehder in 1945 from plants growing in the Arnold Arboretum, the seed parent of which was H. mollis (the Wilson introduction), and the pollen parent a yellow-flowered H. japonica. The foliage of these hybrids was described by Rehder as being intermediate between those of the parents in shape and indumentum. It is very likely that some of the seedlings of H. mollis raised and distributed over the past half-century belong to H. × intermedia. At any rate, plants under the name H. mollis have been noted which differ from that species in having the leaves narrower at the base, darker green above, more sparsely downy beneath and with longer and more slender stalks.
Some of the best known witch-hazel hybrids were raised at Kalmthout in Belgium, where as early as 1902 the nurseryman Kort had a collection of the species and cultivars then known (Rev. Hort. Belg., Vol. 28 (1902), p. 61). Later he must certainly have added the newer introductions, including H. mollis and H. japonica var. flavopurpurascens. In the late 1920s this nursery fell into decay, but after the second world war part of the site was purchased by MM. Georges and Robert de Belder, who have carried on the work started by Kort. In a lecture to the Royal Horticultural Society Robert de Belder said of these Kalmthout hybrids: ‘I am still doubtful about the origin of our plants. I presume that they were originally seedlings of a plant labelled H. japonica var. flavopurpurascens. There are two possibilities: either the plant that we grow at Kalmthout under that name is hybrid already or the plant, being a form of japonica, has been pollinated by mollis and, subsequently, by intermediate forms. Either way, the large intermedia plants that we grow show hybrid vigour and are very fertile. This enables us to raise thousands of seedlings for selection. Flower colour varies from pale to dark yellow, orange, red and dark red’ (Journ. R.H.S., Vol. 94 (1969), p. 85).
Varieties of H. × intermedia have also been raised in Britain, Denmark, Germany and Japan. The following is only a selection, and further information can be found in the works cited in the introductory note to Hamamelis.
‘Arnold Promise’. – A selection from the typical plants of H. × intermedia raised at the Arnold Arboretum, named in 1963. The original plant there, thirty-five years old, is 18 ft high, 20 ft across and colours reddish in the autumn (Wyman, Shrubs and Vines for American Gardens, 1969). It is as yet scarcely known in Britain.
‘Hiltingbury’. – A seedling of H. japonica var. flavopurpurascens raised by Messrs Hillier before 1945. It is inferior in flower to the newer hybrids but the leaves colour well in the autumn.
‘Jelena’. – Flowers bright copper-orange when seen from a distance in sunshine, but the petals are really bi-coloured, described as Jasper Red at the base, passing to Yellow Ochre. Free-flowering and vigorous. A.M. 1955. It was raised at Kalmthout by Kort but first named by MM. de Belder after they took over the property.
‘Feuerzauber’ (‘Fire Charm’, ‘Magic Fire’). – Flowers copper-red, fragrant, the petals about 5⁄8 in. long. Raised by Messrs Hesse of Weener. Said to be an improvement on the older ‘Ruby Glow’ (syn. ‘Adonis’), which was raised by Kort at Kalmthout in 1935 and originally distributed as H. japonica flavo-purpurascens superba.
‘Orange Beauty’. – Flowers deep yellow verging on orange-yellow, fragrant and freely borne. A seedling from H. mollis, pollinated by H. japonica, raised by Heinrich Bruns in Germany and originally distributed under the name ‘Orange’. A variety from Japan, named ‘WinterBeauty’, is said to be similar but with longer petals, brownish red at the base (Grootendorst, Dendroflora, op. cit., pp. 16 and 17).