Berberis thunbergii DC.

A deciduous shrub, of very close, compact habit, from 3 to 8 ft high, with stiff, deeply grooved branches, and glabrous, reddish-brown bark. Leaves crowded in tufts along the branches (the tufts often 1⁄4 to 1⁄2 in. apart), obovate or spathulate, 1⁄2 to 11⁄4 in. long, sometimes rounded at the apex, sometimes spine-tipped, never toothed. The thorns on the branches are about 1⁄2 in. long, almost invariably single, but occasionally three-pronged. Flowers 1⁄3 to 1⁄2 in. across, usually solitary in each tuft of leaves, but sometimes in pairs, each one borne on a slender stalk 1⁄2 in. long; sepals small, dull red; petals twice as long, pale yellow suffused with red. Berries bright red, 1⁄3 in. long. Bot. Mag., t. 6646.

The first European to notice this barberry was Thunberg, who saw it in Japan in 1784, but it did not reach this country until about ninety years later. It has been found wild in China. Latterly it has become popular in gardens, owing to its neat, close habit, its handsome red fruits, but more than all for its brilliant red foliage in autumn. The flowers, although unusual in colour and freely borne, are not showy. In the suburbs of Boston, Mass., in the neighbourhood of the Arnold Arboretum, it thrives remarkably; I have measured bushes there 8 ft high and 15 ft across.

From the Supplement (Vol. V)

This species is unusual among the deciduous kinds in being fairly easily raised from cuttings, and in being very productive of cultivars. Mention is made below of some that have been introduced to Britain in the past fifteen years or so, all raised in Holland unless otherwise stated.

† cv. ‘Aurea’. – Leaves bright yellow, tending to become yellowish green in late summer, and also burning in full sun. Raised in the USA and introduced to Britain late in the 1960s. The form in commerce is low-growing and compact, but it is doubtful whether the name is really clonal.

f. atropurpurea – There are now numerous selections in this group, such as ‘Helmond Pillar’ and ‘Red Pillar’, both of narrowly erect habit; ‘Red Chief’, vigorous and of graceful habit, to about 7 ft high; and ‘Dart’s Red Lady’, of spreading habit, with dark purple leaves, colouring well in autumn.

cv. ‘Atropurpurea Nana’. – Possible improvements on this are ‘Dart’s Purple’, similar in habit but with brighter coloured foliage; and ‘Bagatelle’, very dwarf and slow growing, of rounded habit.

cv. ‘Golden Ring’. – Leaves purple, large, with a gold rim. The name is not strictly clonal, as several similar seedlings were propagated and sent out under it (Dendroflora, No. 9 (1972), p. 32). A similar plant is sold in Britain as ‘Gold Rim’.

† cv. ‘Green Ornament’. – A fairly vigorous green-leaved selection, with ascending branches; free-fruiting. ‘Green Carpet’ is spreading, to 2 ft or so high.

cv. ‘Minor’. – A similar and perhaps better clone is ‘Kobold’, which grows to about 11⁄2 ft high.

cv. ‘Rose Glow’. – Said to be an improvement is ‘Pink Queen’, with a light pink instead of a white variegation.

† B. ‘Parkjuwel’. – A hybrid between B. thunbergii (seed parent) and some evergreen barberry, either B. candidula or B. × hybrido-gagnepainii. It is a dense shrub of roundish habit to about 4 ft high, with almost entire leaves which mostly persist through the winter. Its flowers are of little account. When describing it in 1956, H. J. Grootendorst gave it botanical status as B. × media ‘Parkjuwel’. ‘Red Jewel’ is a sport from this, with red-bronze young foliage.