Naturalisation in Extra- Tropical Countries. 215 



Genista tinctoria, Linne. 



Europe, Northern and Western Asia. A perennial herb, of some 

 medicinal use. From the flowers a yellow dye may be extracted, 

 which with woad gives a good green, and comes well in for domestic 

 dyeing, particularly of wool. A kind of Schiittgelb, different from 

 the one prepared from Maclura tinctoria, is obtained from this 

 Genista, known also as factitium-yellow, and perhaps not 

 altogether to be superseded by picric acid or by Anilin-colors [Or. 

 Don ; Bosenthal ; Brockhaus] . 



Crentiana lutea, Linne. 



Sub-alpine tracts of Middle and Southern Europe. A beautiful 

 perennial herb, yielding the medicinal gentian-root. It could be 

 easily raised in high mountains elsewhere. Chemical principles : 

 gentian-bitter and gentianin. Medicinal gentian-root is also 

 obtained from G. punctata, L., G. purpurea, L. and G. Pannonica, 

 Scop, of the European Alps. The natives of India prize G. Kurroo 

 (Boyle), which ascends the Himalaya to 11,000 feet [Dr. G. Watt]. 

 Several native species are used as substitutes in North- America, 

 particularly G. quinqueflora (Lamarck). Their straying into 

 pasture-land must be checked. 



G-eonoma vag*a, Grisebach and Wendland. 



West-Indies to Brazil. A dwarf decorative Palm, ascending 

 mountain-regions to 3,000 feet. 



G-eum urbanum, Brunfels. 



The " Avens " of Britain. Europe, North- Africa, extra-tropical 

 and alpine Asia, South-Eastern Australia, North- America. A per- 

 ennial herb ; the powerful anti-dvsenteric root, according to Mus- 

 pratt, contains as much as 41 per cent, of tannic acid. 



Gigrantochloa Abyssinica, F. v. Mueller. (Oxytenanthera Abyssinica, 

 Bentham.) 



Tropical Africa. A tall Bamboo, ascending to considerable 

 mountain-elevations. 



Gigrantochloa apus, Kurz. (Bambusa apus, Roemer and Schultes.) 



Indian Archipelagus, at elevations under 5,000 feet. Height of 

 stem reaching 60 feet. When young it is used for strings and 

 ropes. 



Gigrantochloa aspera, Kurz. 



Java. Found by Zollinger to attain a maximum-height of 170 

 feet. 



