An evergreen, dwarf shrub of dense, hemispherical habit, probably never much more than 3 to 4 ft high; the branches rigidly arching, quite glabrous, bright brown, armed at each joint with a trio of stiff, sharp, pale brown spines, up to 5⁄8 in. long. Leaves produced in tufts in the axils of the spines, dark shining green above, vividly blue-white beneath; 1⁄2 to 11⁄4 in. long, 1⁄/6 to 3⁄8 in. wide; oblong or narrowly oval, terminated by a minute, slender spine, and armed with a few similar ones on the recurved margins; very shortly stalked. Flowers bright yellow, somewhat globose, 5⁄8 in. across, solitary, on a slender stalk about 1⁄2 in. long. Fruit oval, covered with a purple bloom, 1⁄2 in. long.
Native of China; first collected by Farges, and raised in 1895 by M. Maurice de Vilmorin. It flowered in 1900, and was figured in the Fruticetum Vilmorinianum, p. 15, as “B. wallichiana var. pallida”. It was later introduced by Wilson for the Veitch nurseries. It is most likely to be confused with B. verruculosa, but that species is of looser habit and the leaves are only glaucous beneath, not conspicuously white as in B. candidula. Its neat, dense habit and slow increase in size make it suitable for the rock garden, but it will in time attain a considerable spread – to 5 ft or even more.
From the Supplement (Vol. V)
The synonym B. wallichiana var. pallida dates from a time when the name B. wallichiana was misapplied by botanists to the species properly known as B. hookeri, to which B. candidula is closely related.
† B. × frikartii Schneid. ex Van de Laar – A group of hybrids between B. candidula and the related B. verruculosa. The type of the group was raised by Messrs Frikart of Stäfa, Switzerland, around 1928, and put into commerce by them as B. × chenaultii 'St[amul]fa'; it has also been wrongly placed under B. × hybrido-gagnepainii. The name B. × frikartii was proposed by Camillo Schneider in 1942 but was not validated until H. J. van de Laar did so in 1972 (Dendroflora No. 9, p. 14). The two clones at present available in commerce show hybrid vigour, and differ from their parents in their lighter green leaves. These are 'Amstelveen' and 'Telstar', both raised in Holland about 1960 and originally placed under B. candidula. The latter has grown very vigorously at Kew, where the original group has already (1983) formed a solid, flat-topped clump about 4 ft high. 'Amstelveen' is slightly less vigorous.