50 THE TRUE GRASSES. 



somewhat hardened first and second empty glumes with 

 long hairs (especially on the callus). Third empty glume 

 (often 0) as well as the flowering glume and short palea 

 h valine. Anthers three. Tall grasses, usually with narrow 

 leaves ; the small spikelets surrounded by long silky hairs. 



Species twelve, mostly in the tropics of the Old 

 World, only three (forming Sec. II) in America. 



Sec. I. Spikelets all £ . Panicles expanded, axis of 

 racemes articulate. To this section belongs S. officina- 

 rum L. (Sugar-cane) (Fig. 13), which has a culm 2-4 m. 

 high, 2-5 cm. thick, with very juicy pith ; leaves long, 2-4 

 cm. broad ; panicles 40-80 cm. long, pyramidal, and the 

 third empty glume wanting. Native country not known, 

 probably from tropical East Asia, but now cultivated in all 

 tropical countries, especially in South America, and also 

 in South Spain. In many countries, especially in the 

 islands of the Pacific Ocean, it readily becomes spon- 

 taneous, and when this is the case it blossoms. For 

 culture varieties are chosen which have been reproduced 

 for centuries by cuttings, and consequently have become 

 nearly incapable of blooming. To propagate sugar-cane 

 it is sufficient to place a piece of the culm possessing 

 buds at its nodes, in a hole or furrow in the ground, 

 where it will root rapidly if sufficiently moist. 



The different cultivated varieties are distinguished 

 almost entirely by the color and height of the culm. 

 The expressed juice or sap yields 17 to 18 per cent sac- 

 charose (crystallizable sugar), and the uncrystallizable 

 molasses that remains is used for the manufacture of 

 rum. In many countries the fresh culms are sold for 

 chewing. At present the colonial sugar industry is 

 somewhat on the decline, a condition to which the manu- 

 facture of beet-sugar and the attacks of certain insects 

 (Tortrix sacchariphaga, Coccus sacchari) have contributed. 

 S. spontaneum L. with narrower leaves and a developed 

 third empty glume is found from Sicily (where it is also 

 cultivated as a hedge plant) through the tropics of the 

 Old World, and is a component of the Alang Alang fields 

 of Sunda Islands (Malayan Archipelago), and of the grass- 

 bars of the "Upper Nile. 



