Sophora tetraptera J.S. Miller

A shrub or small tree, varying from 15 to 40 ft high in the wild, the trunk 6 in. to 2 ft in diameter, usually shedding its leaves before the flowers expand in spring; young branchlets clad with a tawny down. Unlike S. microphylla it does not go through a juvenile phase. Leaves pinnate, 11⁄2 to 6 in. long, with ten to twenty pairs of leaflets, which are 1⁄2 to 13⁄8 in. long, 3⁄16 to 5⁄16 in. wide, ovate or elliptic oblong, appressed silky-hairy on both sides. Flowers somewhat tubular, golden yellow, pendulous, clustered four to ten together in each raceme, opening in May. Calyx silky, obliquely bell-shaped, 1⁄2 in. or more across, shallow-toothed. Standard forward pointing, about two-thirds as long as the keel; wings slightly longer than the standard. Pods 2 to 8 in. long, four-winged, with constrictions between the seeds. Bot. Mag., t. 167.

Native of the North Island of New Zealand, in open places, often by stream-sides, or at the margins of forest; introduced in 1772 by Sir Joseph Banks, who accompanied Capt. Cook on his first exploratory voyage and brought back plants, two of which flowered and fruited in 1779. One of the most beautiful of New Zealand natives, the kowhai is fortunately hardy enough to thrive and flower against a sunny wall over much of the country and is unlikely to be killed outright by frost once it has built up a woody framework. But in cool and rainy localities it may not ripen its wood sufficiently to withstand severe winters. South of London it can be grown in the open in a sheltered spot but remains shrubby. In the milder parts it has attained tree dimensions, as at Mount Stewart in Northern Ireland, 23 × 21⁄4 ft (1976) and Mount Usher, Co. Wicklow, Eire, 26 × 21⁄4 ft. Even at Kew, in a south-facing bay on the Temperate House Terrace it attained a height of 18 ft.

S. tetraptera is well worth growing for its large, showy flowers and its foliage. The remarkable necklace-like pod, with four thin ridges traversing it lengthwise, is quite often seen in this country. S. tetraptera received an Award of Merit in 1943 when shown by the University Botanic Garden, Cambridge.

From the Supplement (Vol. V)

specimens: Morrab Gardens, Penzance, Cornwall, 28 × 2 ft and other stems (1979); Mount Stewart, Co. Down, 26 × 21⁄4 ft (1976); Ballywalter, Co. Down, on wall, 41 × 81⁄2 ft at 1 ft (1982); Mount Usher, Co. Wicklow, Eire, 26 × 21⁄4 ft at 4 ft (1975).

† cv. ‘Gnome’. – In New Zealand gardens the species normally attains a height of about 20 ft. This cultivar is slow-growing to about 8 ft high, stiffly and erectly branched, with flowers about 21⁄4 in. long. It may start to flower when only some 1 ft high (Metcalf, Cult. N. Z. Tr. and Shr., p. 258).