Naturalisation in Extra-Tropical Countries. 585 



recently into medicinal use. The occasional attacks of particular 

 kinds of rust, smut and blight must be overcome by the same 

 measures, adopted against similar parasitic fungs on wheat. Ustilago 

 Maydis (Corda) can in particular become extensively destructive to 

 maize-crops. Z. canina [S. Watson] recently discovered near Lake 

 Cuiztko, close to the boundary-line between the states Guanajuato 

 and Michoacan, is either the wild plant from which Z. Mays origi- 

 nated or a new distinct species. 



Zelkova acuminata, Planchon. (Planera acuminata, Lindley ; P. Japonica, 

 Miquel ; Zelkova Keaki, Savatier and Franchet.) 



The " Keaki " Japan. Considered one of the best timber-trees 

 there ; height up to 160 feet ; stem-diameter to 10 feet [Prof, 

 Luerssen]. Likes calcareous soil. It proved of rapid growth and 

 valuable as a shade-tree also at Melbourne. The wood never 

 cracks, and is hence most extensively used for turnery, also much for 

 furniture [Rein] . For out-door work the most valued wood in Japan 

 [Christy]. 



Zelkova crenata, Spach. (Planera Richardi, Michaux. ) 



South-Western Asia, ascending to 5,000 feet. In favorable 

 localities a good-sized tree, with qualities resembling those of the 

 elms. Growth of comparative celerity. Resists severe frosts. Its 

 tendency to form straight and tall stems with few and short 

 branches is evident. Attains an age over 200 years ; rate of growth 

 about 2 feet a year. Medwedieff calls this tree the pearl of the 

 Caucasian forests. The propagation is either from seeds or layers 

 or cuttings [H. Scharrar]. The wood is pale-yellowish and streaked, 

 tough and elastic, heavy, hard, fine-grained, neither rends nor 

 warps ; also under ground never infested with insects, almost im- 

 perishable. The allied Z. Cretica (Spach) is restricted to South- 

 Europe. 



Zingiber officinale, Roscoe. 



The Ginger. India and China. Possibly this plant may be pro-* 

 ductive also in the warmer temperate zone, and give satisfactory 

 results. In Jamaica it is cultivated up to an elevation of 3,500 feet 

 [W. Fawcett]. The multiplication is effected by division of the root. 

 In the lower Himalayan region, where the temperature is already 

 too low in the cool season, the Ginger -roots are lifted and stored, 

 portions to be replanted when the warm weather sets in [W. 



. Gollan]. This principle may be applicable to many other plants in 

 particular regions. For candied ginger only the young succulent 

 roots are used, which are peeled and scaled prior to immersion into 

 the saccharine liquid. Great Britain imported in 1884 about 56)000' 

 cwt. of ginger, valued at 124,000. 



