CLASSIFICATION OF AMERICAN WHEAT VARIETIES. 185 



Spike Awned— Continued. 

 2b. Glumes Pubescent. 

 3a. Glumes White. 

 4a. Awns Black. 



5a. Kernels White ( T. d. melanopus AL). 



Kernels Long, Hard. Page. 



Beaks 1-2 mm. long Velvet Don 191 



Beaks 1-5 mm. long Golden Ball 191 



3b. Glumes Black. 

 4a. Awns Black. 



5a. Kernels White ( T. d. taganrogense Desv.). 

 Kernels Long, Hard. 



1-2 mm. long Kahla 192 



DESCRIPTIONS, HISTORY, DISTRIBUTION, AND SYNONYMY OF DURUM WHEAT 



VARIETIES. 



PENTAD (D-5). 



Description. — Plant spring habit, midseason, midtall ; stem white, midstrong ; 

 spike awned, fusiform, middense, inclined ; glumes glabrous, white, midlong, 

 midwide ; shoulders midwide, oblique to elevated ; beaks 1 to 2 mm. long ; 

 awns white, 5 to 15 cm. long; kernels red, midlong, hard, ovate, truncate tip, 

 humped; germ midsized; crease midwide, shallow; cheeks angular; brush 

 midsized, short. 



The Pentad or D-5 (Durum No. 5) variety is distinct from all other com- 

 mercial varieties of durum wheat grown in the United States because of its 

 red kernels. They are smaller, squarer at the brush end, and more pointed at 

 the germ end than kernels of the other durum varieties. Experiments have 

 shown it to be the most rust-resistant variety of wheat grown in the United 

 States, and therefore it yields well under conditions favoring rust. Its milling 

 and baking value, however, has been found to be inferior to other durum varie- 

 ties. A spike, glumes, and kernels of Pentad wheat are shown in Plate LV, A. 



History. — The Pentad variety was introduced from Russia in 1903 by Prof. H. 

 L. Bolley, of the North Dakota Agricultural Experiment Station. The wheat was 

 distributed in several sections of North Dakota by Professor Bolley in the 

 spring of 1911. Because of its rust resistance it gained popularity and has 

 recently become widely distributed in the durum-wheat section, but its poor 

 milling quality has caused its distribution to be opposed by many agencies. 

 The name Pentad is derived from penta, meaning five in Greek, plus d, which 

 stands for durum. The name was suggested to the North Dakota station by 

 the senior writer in 1917. It has recently been used by Professor Bolley as a 

 name for D-5, and was first recorded by Trowbridge (196, p. 17) in 1920. 



Distribution. — Pentad was reported in 1919 from Minnesota, Montana, Ne- 

 braska, North Dakota, South Dakota, and Wyoming. It is grown principally in 

 North Dakota. 



Synonyms. — " D-fife," Ladd Durum, Red Durum, Resistant Fife, and Rust 

 Proof. 



The name " D-fife " is often but wrongly used by many farmers in North 

 Dakota. The practice is easily accounted for, as the numeral 5 has been mis- 

 pronounced as fife. Ladd Durum is a name used in the grain trade for Pentad 

 wheat under the supposition that Dr. E. F. Ladd, formerly of the North Dakota 

 Agricultural College, was the originator. Red Durum is a name commonly 

 used for Pentad wheat, as it is the name of the subclass under which the grain 

 of this wheat is graded under the Official Grain Standards. Resistant Fife 

 and Rust Proof are names used for Pentad wheat on the farms, because the 

 variety has proved to be resistant to stem rust. 



