TRITICUM III 



Spikelets more than two-flowered, two or more fertile; terminal spikelct 

 developed; lateral teeth of glumes obtuse; palet remaining entire at 

 maturity. 

 Glumes as long or usually longer than lemma; palet about two-thirds 



as long as lemma. T. polonicum (Polish wheat) . 

 Glumes shorter than lemma; palet nearly as long as lemma. 



Rachis brittle, articulated, breaking at nodes when threshed, the seg- 

 ments remaining attached to spikelets; spikelets two-grained (some- 

 times three in spelt). 



Spikelets not set thickly on stem; arched on inner side; adhering por- 

 tion of rachis thick, blunt; stem above with central canal. T. 

 spella (spelt). 

 Spikelets set thickly on stem; flattened on inner side; adhering portion 

 of rachis slender, pointed; stem above, with e.xception of narrow 

 canal, fiUed with pith. T. dicoccum (emmer). 

 Rachis tenacious, not articulated, remaining entire in threshing; spikelets 

 usually more than two-grained. 



Empty glumes sharply and broadly keeled to the base; lemma 

 bearded. 

 Spike with sides parallel or nearly so; glumes with a bloom, usually 

 glabrous; grain very hard, horny, long. T. durum (durum 

 wheat). 

 Spike short, crowded, long-ovate; glumes usually pubescent; grain 

 short, blunt and softer than that of T. durum. T. lurgidum 

 (Poulard wheat). 

 Empty glumes keeled in upper half; rounded below (sometimes 

 slightly keeled in lower half); lemma sometimes bearded. 

 Spikes very short (rarely over 2 inches) ; very compact or crowded; 

 thicker at apex than center or base; grains small, short. T. 

 compactum (club wheat). 

 Spikes longer than 2 inches, open; sides usually parallel or nearly 

 so. T. asllvum- (common bread wheat). 



The types of wheat fall into two natural groups, as to 

 attachment of lemma and palet to grain, as follows: 



1. ''Naked wheals,'' in which the grain comes free from the 

 lemma and palet, and the rachis is tenacious (2\ durum, 

 turgidum, compactum, cdsiivum, and polonicum) . 



2. ''Spelt wheats," in which the grain remains altaclicd 

 to the lemma and palet, and the rachis is fragile {2\ ■moiio- 

 coccum, dicoccum, and spelta). 



