ZANTHOXYLUM 691 



leaf-stalks, the trifoliolate or pinnate, alternate leaves, the small, mostly 

 unisexual flowers, the two-valved roundish capsules which split downward, 

 and the shining black or blue seeds which, after the bursting of the 

 capsules, often remain for some time attached by a short thread. 



These species are not in the first rank of ornamental shrubs, but well- 

 grown specimens are handsome in foliage. They like a good deep soil, 

 and are best propagated by seeds ; when these are not available they may 

 be increased by cuttings made of the young wood in July, or of the roots 

 in spring. The fruits arid seeds of some species have a pungent pepper- 

 like taste and are used as a condiment, and the bark contains a powerful 

 stimulant and tonic principle sometimes employed in medicine. The 

 generic name, sometimes spelt Xanthoxylum, refers to the yellowness of 

 the wood of some species. 



Z. AILANTHOIDES, Siebold. 



A deciduous tree, 50 to 60 ft. high in Japan, the branchlets very stout, 

 not downy, densely set with short, stiff spines. Leaves pinnate 'and variable 

 in size; on young trees at Kew they have been 3 ft. long, but ordinarily are 

 from 10 to 18 ins. Leaflets in from five and a half to eleven and a half pairs, 

 each one 2 to 5 ins. long, ovate or ovate-lanceolate, finely toothed, smooth, 

 dark green. Flowers in a flat corymb 5 ins. or more across, whitish with 

 yellow stamens; two or more corymbs are associated at the end of the 

 branch. Seeds black, compressed and tapering to one end. 



Native of Japan and Formosa; often introduced, but unfortunately tender 

 and only adapted for the south-west counties. It rarely survives more than 

 one or two winters at Kew. As its name implies, this tree resembles an 

 Ailanthus in its long, handsome, pinnate leaves. 



Z. AMERICANUM, Miller. PRICKLY ASH. TOOTHACHE TREE. 



(Z. fraxineum, Willdenow.} 



A spreading, round-headed, deciduous shrub, usually 6 to 10 ft. high in 

 this country, but capable of growing twice as high; young shoots brown, 

 downy, becoming smooth and grey with age; armed with stiff spines \ in. 

 or less long, in pairs. Leaves pinnate, 6 to 8 ins. long with usually five to 

 eleven, but sometimes thirteen, leaflets, often with one or two spines on 

 the main-stalk where the leaflets are attached. Leaflets i j- to T.\ ins. long, 

 ovate or oval, downy beneath especially on the midrib, minutely or not at 

 all toothed. Flowers crowded at the joints of the previous season's shoots, 

 very small, yellowish green. Fruit a blackish, fragrant, two-valved capsule; 

 seeds black and shining. 



Native of the eastern United States; introduced during the middle years 

 of the eighteenth century. This shrub is said to have been at one time 

 common in gardens; it is no longer so. The bark and capsules have a 

 pungent, acrid taste, and one of the popular names is given because they 

 have been chewed to alleviate toothache. It is very easily distinguished 

 from the other species here included by the very downy under-surface of 

 the leaves. 



Z. BUNGEI, Planchon. 



A deciduous bush of graceful, spreading habit 10 ft. or more high; said 

 sometimes to be a small tree over 20 ft. high. Branchlets downy or smooth, 



