A tree 60 to 70 ft high, the trunk and branches very formidably armed with branched, slightly flattened spines; young shoots on plants at Kew dark purplish brown, smooth and shining. Leaves simply or doubly pinnate, 8 to 12 in. long, each leaf or leaf-section carrying fourteen to twenty-four leaflets. Leaflets ovate to lanceolate, often unequal at each side of the midrib, blunt to pointed at the apex, margins entire; main-stalk, midrib, and stalk of leaflets downy. In Japanese fruit-bearing specimens the leaflets are 3⁄4 to 11⁄2 in. long, 1⁄4 to 1⁄2 in. wide, but in small cultivated trees they are only 1⁄3 to 5⁄8 in. long. Pods 8 to 10 in. long, 1 to 11⁄4 in. wide, scimitar-shaped, ultimately twisted.
Native of Japan; introduced to Kew in 1894, where young trees raised from seed supplied by Boehmer are quite hardy, although slow-growing. When the plants are young, the small leaflets give them a very different aspect to mature specimens, but they are unsurpassed among hardy trees in their fern-like elegance. The species appears to be allied to G. caspica, under which by one authority it has been placed. The pulp in the pods, as in G. sinensis, is saponaceous, and is used by the Japanese for washing cloth.
There are five examples of this species at Kew; two, from the 1894 introduction, are rather flat-topped, not very shapely trees, about 30 ft high.
G. delavayi Franch. – This species, which seems to be closely allied to G. japonica, was introduced by Wilson to Veitch’s Coombe Wood nursery in 1900, during his visit to Yunnan. But according to Elwes and Henry (Tr. Gt. Brit. & Irel., Vol. 6, p. 1513), all the seedlings there were killed in the winter of 1905-6. A dried specimen from a tree once cultivated at Kew under the name G. delavayi is not that species but agrees better with G. heterophylla Bge, a native of N.E. China, not treated in this work. A tree now in the Kew collection, received as G. delavayi from a nursery, is also wrongly named, but of uncertain identity.