Berberis L.
Evergreen or deciduous shrubs, sometimes small subshrubs, usually glabrous or nearly so; wood yellow. Lvs on short or spur shoots simple, often with spiny margins; lvs on long shoots usually modified to form (1)-3-(5)-partite spines. Fls solitary, or in fascicles, racemes (sometimes pseudo-umbellate) or panicles, bracteate, axillary. Perianth segments 12 or 15, consisting of 6 or 9 sepals and 6 petals, imbricate, pale yellow to orange; innermost petals with nectariferous glands at base. Stamens 6, usually sensitive to touch; stigma sessile or on short style. Berry red or black, often with glaucous bloom, (1)-2-(several)-seeded.
Key
c. 400-450 spp., N. temperate regions and temperate S. America. Naturalised spp. 5.
In addition to the spp. described below a number of other spp. and hybrids are cultivated in N.Z., mainly in colder areas, and one of these is very common and sometimes grows spontaneously in gardens at some distance from the parents. This is B. thunbergii DC. from Japan; a small, dense, glabrous, deciduous shrub usually < 1 m high; lvs entire, elliptic-obovate, 1.5-3.3 cm long, often turning orange-yellow to red before falling; spines simple; fls 1-5 in fascicules or pedunculate clusters; frs freely produced, oblong, shining, scarlet, 7-9 mm long. Cv. 'Atropurpurea' is probably commoner than the ordinary green-leaved plant and seedlings from purple-leaved plants often have purple lvs also.
B. thunbergii superficially resembles the unrelated B. wilsonae described below but the characters given above will distinguish them.
