184 BULLETIN 1074, U. S. DEPARTMENT OF AGRICULTURE. 
in 1919 is shown in Figure 75. The durums furnish the great bulk of 
the world’s supply of wheat for the manufacture of semolina, maca- 
roni, and spaghetti. The production of durum wheat in the United 
Fic. 75.—Outline map of the United States, showing the distribution of durum wheat in 
1919. Estimated area, 4,340,000 acres. 
States made possible a large macaroni industry, which now uses 
about a third of the national production of this wheat. The re- 
mainder is exported or used by American mills or bakeries for mix- 
ing with other wheats or flour for bread making. 
‘The varieties that are commercially grown are distinguished by the 
accompanying key. 
KEY TO THE VARIETIES OF DURUM WHEAT. 
la. SPIKE AWNED. 
2a. GLUMES GLABROUS. 
3a. GLUMES WHITE. 
4a. AWNS WHITE. 
5a. KERNELS RED ( Triticum durum affine Kceke.). Page. 
IGERNELS) MIDDONG, HDARDE 222225. 29 -f455-525- =-8- BENTAD22 5 SeBce Sa se cocker 185 
4b. AWNS BLACK. 
5a. KERNELS Waite (AMBER) (T. d. leucomelan Al.). 
KRNELS VERY MuONG)| HARD! 6... i 242522255. S285 PELISSS7 293... fsaeciaee eons 186 
3b. GLUMES YELLOW. 
4a. AWNS WHITE. 
5a. KERNELS WHITE ( 7. d. hordeiforme Host.). 
KERNELS LONG, HARD. 
Spike fusiform. i 
Plant midtali; beaks 1-2 mm. long......... A CMES SEER EERE eet 186 
MONAD -< cece sete eee see 187 
Plant tall; beaks 1-5 mm. long. ...........-/ A RIN AU IDKAS! SoS ieee ee 187 
MIND UATSe I: eke Seer: ae 188 
Spike oblong; plant tall. ; 
Beakst—2 mir lone eceeosettenenecenee eee KUBICA oo cee ere nen ae 189 
KUBANKA No. 8..........- 190 
BUFORD: =-coe es eoce aes Cae 190 
Beaks 1=10mim lone ss-cceecceniacueencecees MAROUANINS > Soa ne siseen as 190 
