246 Journal of Agriculture, Victoria. [10 April, 1919. 



AN ECONOMIC PLANT. 



THE JERUSALEM ARTICHOKE. 



By J. W. Audas, F.L.S., F.R.M.8., Assistant, National Herbarium, 



Melbourne. 



The Jerusalem artichoke (Helianthus tuherosus), a phiut of the 

 natural order Compositse, is a native of North America. It is a 

 hardy perennial herb with rod-like stems 6 to 8 feet in height, and 

 many subcordate petioled leaves and clustered tuberous roots. There 

 are several varieties, which are distinguished by the colour of the 

 tubers — red, white, and yellow — ^and by the shape of the leaves, which 

 are either narrow or broad. Tiie tubers (rhizomes) are used as a 

 vegetable principally during the winter, sometimes as a dish, but more 

 generally for flavouring purposes. They are considered both w^holesome 

 and nutritious, and may be given to invalids when abstinence from 

 other vegetable food is necessary. Before the potato became plentiful 

 they were widely used in Europe, and they are still in great demand 

 there for flavouring soups. 



Jerusalem artichokes or topinambour are extensively cultivated in 

 France for distilling purposes (as are potatoes and beet roots), yielding 

 as much as 7 to 9 per cent of absolute alcohol. According to Payen. 

 the average analysis of the tubers of Jerusalem artichokes is as 

 follows : — 



Water .. .. .. •• •• 76.04 



Glucose and crystallizable sugar . . 14.70i 



1. Inulin ./ .. . . . . 1.86 



100.00 



1. Inulin belongs to the amyloid group of the canbo-hydrates, and 

 occurs in the roots of some plants, among which may be mentioned, in 

 addition to the Jerusalem artichoke, the dahlia. Inulin is intermediate 

 between gums and starch, and yields fermentescible sugar by prolonged 

 boiling with dilute acid. 



2. Of the mineral salts, more than one-fifth is potasli. 



The composition of these tubers varies very much, according to the 

 time they are dug up. The percentage of crystalline sugar _ i.s largest 

 during the cold season, while, during the summer, starch — like inulin, 

 gumniy matters, and glucose— prevails. The tubers form very late, and 

 sliould not be dug before the stems fade ofl", viz, in the autumn. 



Cultivation. 

 The plant will succeed on a variety of soils, but generally gives the 

 best results when grown on rich sandy loams. To insure the most 

 successful results, trench over a piece of ground in the autimm and 

 give a light dressing of nitrogenous and potassic manures, fork over 

 fn September, and then plant good-shaped tubers in rows about 3 feet 



