186 Royles Illustrations of the Natural Histdry 



known for its acid leaves, and as a substitute for Rumex Acetosella, is repre- 

 sented in India by O. corniculata, whicii is there called chooha tipputtee, or 

 three-leaved sorrel, and prescribed as a cooling medicine. The roots of Oxalis 

 tuberosa are eaten in Chili, when cooked. Those of O. crenata, a plant of 

 Columbia, bearing tubers like small potatoes, is one of those called arracacha, 

 and has been introduced into England as a substitute for that invaluable root. 

 It might be so into India, and be useful wherever the soil and climate are 

 better suited to it than to the potato." 



ZygophyllecB. — The most important species of this family is 

 Guaiacum officinale, celebrated for its sudorific properties ; it is 

 found in the West Indies, and might be cultivated in Bengal. 



'Rutdcece. — jRiita albiflora is common in the Himalayas, at 

 elevations of from 5000 ft. to 8000 ft., and would possibly stand 

 the open air in Britain as well as the common rue. This last 

 plant, in dry calcareous soils which are somewhat rich, forms 

 one of the most beautiful of evergreen shrubs, attaining a height 

 of 6 ft. or 8 ft. ; as may be seen in the gardens in some of the 

 old chalk pits in the neighbourhood of Greenhithe in Kent. 



JDiosmcce. — Diosma altaica is found in the Himalayas, and 

 also Z)ictamnus hinialayanus. 



Xanthoxylece The genus Xanthoxylum is overspread in 



different parts of its substance with vesicles of essential oil, 

 which cover the leaves with transparent dots. This oil is the 

 cause of the aromatic pungency of the different species of this 

 genus ; and hence, in India, the capsules and seeds of X. hostile 

 are employed for intoxicating fish, and are chewed as a remedy 

 for the toothach. Different species of Xanthoxylum, Todddlia, 

 and Brucea are found in the Himalayas, and would probably 

 stand in the open air in Britain. 



Simarubacese. — In the Himalayas this order is represented by 

 Nima quRssioides ; but, as it grows only in moderate ele- 

 vations, it may probably not stand the open air in Britain. 

 The Himalayas support an Indian flora at their base and 

 within "their valleys: European as we ascend; and "almost 

 polar on the summits of their lofty mountains, which only for 

 a few months in the year are freed from their covering of 

 snow." Under this order Mr. Royle has introduced an interest- 

 ing comparison of the flora of the north of India with that of 

 Egypt; pointing out what useful plants might be supplied by 

 the former country to the latter, and what from Europe to both. 

 He observes, in a note, that " the present intelligent ruler of 

 Egypt, when lately sending an unlimited order for plants to be 

 sent to him from England, particularly specified the useful 

 plants of India." (p. 162.) Our friend, the Bey Galloway, the 

 pacha of Egypt's* chief engineer, who is now (Feb. 1835) in 

 London, informs us that the teak tree grows vigorously in the 

 government garden at Grand Cairo, under the direction of Mr. 

 Trail, an Englishman, with whom we expect soon to be in cor- 



