An evergreen shrub 3 to 5 ft high, producing a dense thicket of erect, angled stems, which branch near the top; young twigs not downy; spines usually three-forked, each fork slender, rigid, from 1⁄2 to 1 in. long. Leaves in tufts, lanceolate to obovate; 1 to 3 in. long, 1⁄2 to 1 in. wide; leathery, almost stalkless; dark green above, glaucous white beneath; the margins armed with slender teeth. Flowers solitary on their stalks, borne in clusters of three to six at each tuft of leaves; 2⁄3 in. across, pale yellow, the sepals tinged with red. Berries narrow, cylindrical, 1⁄2 in. long, tapering towards the end; black-purple, often remaining on the plant until the following spring. Bot. Mag., t. 9153.
Native of the Himalaya. This shrub has been so much confused with B. wallichiana of De Candolle, that it is hard to disentangle the histories of the two. The true B. wallichiana is probably not in cultivation; it differs from B. hookeri in the larger leaves (3 to 43⁄4 in. long), and especially in their veining; the veins branch out from the midrib, parallel with each other, but never reach the margin, becoming merged in a vein which runs parallel with it. In B. hookeri, the veins fork near the margin, but do not merge into one another. B. hookeri flowers in April and May, and as a rule is quite hardy.
var. viridis Schneid. – Leaves uniformly bright green beneath. Although a marked characteristic of some plants, the white under-surface of typical B. hookeri is not a wholly reliable distinctive character. I have seen young plants partly bright green and partly blue-white beneath.
The best way to increase this species and the above variety is by seed; they may be sown in shallow boxes or in pots, and the young plants pricked out the following years into nursery rows. Both the type and the variety viridis, which is the commoner in cultivation, are useful shrubs for planting in places where an evergreen is wanted that will keep fairly dwarf without pruning.
B. manipurana Ahrendt – This plant has been long grown in gardens as “B. hookeri var. latifolia” – a name based on B. wallichiana var. latifolia Hook. f. & Thoms., which is not in cultivation. It has also been grown as “B. knightii” and “B. xanthoxylon”. B. manipurana is a much taller and more robust shrub than B. hookeri, but not so hardy. It differs, too, in the considerably longer leaves (sometimes over 4 in.), which are glossy on both sides. It is a native of Manipur, whereas B. hookeri appears to be confined to the main Himalayan range.
From the Supplement (Vol. V)
B. manipurana, mentioned under B. hookeri, is out of place there, since its relationship is with the true B. wallichiana, not with B. hookeri, which was once wrongly known as B. wallichiana. A full description of it is given below.
A probable hybrid of B. hookeri var. viridis was named by Dr Ahrendt B. × interposita, the other parent being B. verruculosa, whose influence shows in the warted stems, the greyish undersides of the leaves, the solitary flowers and the dense habit.