An evergreen shrub with clustered stems, free from down in all its parts, 6 to 8 ft high, the branches set with three-parted spines 1⁄2 to 3⁄4 in. long. Leaves of firm texture, 11⁄2 to 4 in. long, 1⁄4 to 1⁄3 in. wide; linear-lanceolate, tapering to a fine point; dark dull green, the margins undulated and set with slender, forward-pointing teeth. Flowers in clusters of about six (sometimes ten or twelve) at each tuft of leaves, each flower on a slender stalk 1⁄2 to 3⁄4 in. long, bright yellow, 1⁄2 in. across. Berries black, covered with blue bloom, oval, 1⁄3 to 5⁄8 in. long, 1⁄4 in. wide. Bot. Mag., t. 8185.
Native of Szechwan, China, introduced for Messrs Veitch by Wilson about 1904. This fine species is one of the most useful of Wilson's introductions from China, being evergreen, of compact, neat habit, and flowering abundantly. Allied to B. hookeri, it is of more graceful habit. The plant described above is the form commonly cultivated. It has longer leaves than in the type and has been distinguished by Dr Ahrendt as var. lanceifolia. It is quite hardy at Kew, and free growing. It flowers in late May. Bot. Mag., n.s., t. 504.
cv. 'Fernspray'. – A form with light green, crinkle-edged leaves, put into commerce by Messrs Jackman of Woking. It makes an elegant specimen to about 6 ft high and almost as much wide and is also recommended as a hedging plant.
B. × chenaultii Ahrendt – The typical form of this cross, which is B. gagnepainii × verruculosa, was raised by Chenault of Orleans around 1933 and put into commerce in this country by Messrs Hillier. It is a rather slow-growing shrub with arching branches and glossy leaves, but otherwise much resembles the first parent.
From the Supplement (Vol. V)
The species with which B. gagnepainii is most likely to be confused is B. veitchii, distinguishable by its red young stems, very pale brownish yellow flowers and spreading habit. The narrow-leaved B. triacanthophora is rare in this country but cultivated in the USA; this has dark red mature stems, whereas B. gagnepainii and B. veitchii are yellowish. B. panlanensis has narrow leaves, but they are oblong and normally not much over 15⁄8 in. long. See also B. soulieana in this supplement.
† B. × hybrido-gagnepainii Suringar (1929) B. × chenaultii Ahrendt (1961); ?B. × wokingensis Ahrendt, nom. nud. – This name is founded on a hybrid berberis raised in Holland and called 'Terra Nova'. Suringar considered that the parentage was B. candidula × B. gagnepainii, but it is now held that B. verruculosa and not the first named species was involved. The cross is mainly represented in this country by 'Chenaultii', raised by Chenault of Orleans about 1933, and distributed in this country by Messrs Hillier. It is a rather slow-growing shrub to about 5 ft high, with arching branches and glossy lanceolate leaves up to about 2 in. long and 1⁄2 in. wide, but otherwise much resembles B. gagnepainii.
Also coming under B. × hybrido-gagnepainii is 'Wallich's Purple', raised in Holland; it was originally distributed as B. wallichiana purpurea, and renamed in 1965. In habit and shape of leaf this is rather like B. × frikartii 'Amstelveen' and 'Telstar' (see under B. candidula), but the leaves are grey-green beneath, purplish when young. At Kew it is inferior to 'Telstar', being less leafy.