172 



PSOPHOCARPUS TETRAGONOLOBUS (POIS CARRE) 



Madagascar, it is fairly likely that the species tetragono- 

 lobiis, which closely resembles it, is of the same origin." 



The fact is that the point is far from being settled. What 

 is certain is that the species palustris grows wild in the 

 Comoros and Madagascar. 



The variety grown in JNlauritius has no tubercles : these 

 are simply swellings of the roots where starch is stored up 

 and which increase in size as the plant grows older. They 

 form reserves on which the plant draws the following year, 

 during its early growth. These reserves disappear, and the 

 plant gives off other roots wliich nourish it and which act as 

 new reserves when growth is finished. 



In a trial we made on plants after two years' growth we 

 obtained the followingf results : — 



Roots taken from four plants gave the following 

 weights : — ■ 



I 



2 



3 

 4 



717 gr- 



785 „ 



These roots, after the adherent earth had been removed 

 by washing, yielded a proportion of 30*8 per cent, of outer 

 layers ("skins") ij to 2 mm. thick. 



In the decorticated root a content -of i5'8 per cent, of 

 starch was found, which in terms of the whole root does not 

 amount to more than io'q per cent. 



The proximate composition of the decorticated roots was 



follows : — ■ 



a 



Water 



Ash 



Cellulose 



Fat 



Sugars 



Non-nilrogenous matter 



Nitrogenous matter ... 



Nitrogen 



These roots have a fairly agreeable flavour when boiled, 

 and might be used as food if they could be thoroughly 



