A shrub 20 to 25 ft high. Leaves 2 to 21⁄2 ft long, with seventeen to twenty-seven leaflets, the lowermost pair very small, roundish, inserted about 1⁄2 in. above the base of the rachis. Leaflets (except the basal pair) oblong-ovate or oblong-lanceolate, mostly 2 to 4 in. long, 1 to 15⁄8 in. wide, the middle pairs the longest, the lowermost pairs the widest, acute at the apex, truncate at the base, leathery in texture, slightly glossy above, three- to five-veined from the base, the veins slightly impressed above and raised beneath, margins sinuately toothed, with three to seven teeth on the lower margin, two to five on the upper. Racemes stout, spreading, terminal, in clusters of three or four, up to 12 in. long, with numerous densely arranged deep yellow flowers. Berries purple, covered with a bluish bloom, ovoid, about 3⁄8 in. long, crowned by a short, persistent style.
Native of the Himalaya from Kumaon to Assam, and of the Naga Hills. Although included in M. napaulensis by Hooker and Thomson, it is now usually regarded as a distinct species, differing chiefly in the longer leaves with more numerous leaflets. Other differences given by Dr Ahrendt are that the leaves are less glossy than in M. napaulensis and that the fruits bear more conspicuous styles. In cultivated plants there is also a difference in flowering time: late autumn and early winter for M. acanthifolia, early spring for M. napaulensis. In foliage M. acanthifolia is the finest of all the species that can be cultivated in the open in the British Isles. It is hardy in the southern and western parts of the country, but needs a sheltered position. It received a First Class Certificate when shown from Windsor Great Park on 25 November 1958. The plant in the Savill Gardens, growing on a wall near the propagating houses, is a cutting from the F.C.C. plant; it has attained a height of 9 ft in twelve years (1971).
M. napaulensis DC. – The mahonia described in previous editions under this name was really M. acanthifolia, which is part of M. napaulensis as understood by many botanists until recently. With M. acanthifolia separated from it, M. napaulensis becomes a species of little garden merit, being less hardy and not so handsome. The leaves have fewer leaflets – up to fifteen – and are therefore shorter than in M. acanthifolia. It is reported to be an inhabitant of the mainly evergreen type of forest that occurs in Nepal and Sikkim at 6,000 to 9,000 ft. The cultivated plants flower in early spring, i.e. later than M. acanthifolia, but this difference does not hold good for all the wild plants.
M. napaulensis is in cultivation at Wakehurst Place, Sussex, from seeds collected by A. D. Schilling in Nepal, and there is a plant in the Savill Gardens, Windsor, introduced from the same region by Dr Herklots. At Kew there is a plant about 8 ft high in the Temperate House. The cultivar ‘Maharajah’ is in cultivation at Wakehurst Place and in the Savill Gardens; this descends from a plant once cultivated in Guernsey, and bears flowers of a deep yellow.