58 LEAVES 



less prominent on the upper surface, but the leaves are not all equally 

 hairy. 



Both stalks and fruits are frequently found mixed with the leaves ; 

 the former are characterised by the swollen nodes which distinguish 

 Piperaceous plants ; the latter are long, slender, cylindrical spikes. 



The leaves have a slight, aromatic odour and an aromatic, cam- 

 phoraceous, somewhat bitter taste. Although the mesophyll contains 

 oil-cells, they cannot easily be seen even with a strong lens if the leaf 

 is very hairy. 



The student should observe 



(a) The veinlets depressed on the upper surface, prominent 



on the under surface, 



(b) The shaggy hairs, 



(c) The characteristic taste ; 



and should compare the leaves with 



Foxglove leaves, in which the veinlets are not depressed and the 

 taste not aromatic. 



Constituents. Matico leaves contain volatile oil (1 to 3*5 per 

 cent.), tannin, crystalline artanthic acid, and a bitter principle which 

 has not yet been satisfactorily examined. The volatile oil has the 

 sp. gr. 0*93 to 0*99 and deposits on cooling matico camphor. 



Varieties. Leaves of the following species of Piper have been 

 identified in commercial matico. They differ from those of P. 

 angustifolium in appearance, and vary also in the quantity and 

 composition of the volatile oil : 



P. lineatum, Ruiz and Pavon ; volatile oil contains no matico 

 camphor. 



P. camphoriferum, de Candolle ; volatile oil contains matico 

 camphor and borneol. 



P. angustifolium, var. fi-ossanum ; volatile oil possibly contains 

 matico camphor and borneol. 



P. acutifolium, var. subverbascifolium ; volatile oil contains pinene 

 and dill-apiol. 



Uses. Matico is used as an aromatic astringent in inflammatory 

 conditions of the urinary passages. 



BETEL 

 Betel. 



Source, &C. Betel leaves are obtained from Piper Betle, Linne 

 (N.O. Piperacece), a shrub indigenous to and cultivated in India and 

 the Malay Archipelago. The leaves are collected, put into baskets, 



