88 TRIANDRIA. DIGTNIA. 



scabrous. Calix smooth, nerveless, exterior valve in the 

 outer flowers setaceous from its base, the inner valves ob- 

 liquely dilated, and rigidly coriaceous, all awned, the in- 

 ner divisions of the lateral flowers, appearing nearly se- 

 mi-ovate, the central ones sublanceolate. Corolla nerve- 

 less, the inner valve furnished with a short awn, arising 

 from its base. Nearly allied, apparently, to the H. inari^ 

 Hmum. 



On the arid and saline plains of the Missouri. 



o. JTtbatiim. On the calcareous islands of Lake Huron 

 and Michigan, also on the banks of the Missouri. 



The genus Hordeum exists chiefly in Europe, Extend- 

 ing into Northern Africa, and Tartary in Asia. The 2 

 species above described are natives of North America, 

 and tlie /'. juhatinn is also common to Smyrna. 



120. SEC ALE. L. (Rye.) 



Calix 2-valved, valves opposite, or 1-valved 

 and many-flowered; gluine.s linear-lanceolate, 

 smooth, or channelled on either side; exterior 

 valve terminated by a long awn. — Flowers 

 spiked, rachis toothed. 



Species. 1. S. cereale. Cultivated. No where nata- 

 r.lj^efl or indigenous in the United States. Native in the 

 isle of Crete. 



m. TRITICUM. L. (Wheat.) 



Calix 2-valved, solitary, many-flowered; 

 valves parallel to the rachis. Flowers some- 

 what obtuse, ghimes unarmed, or interruptedly 

 awncd. Spikelets rather short, approximating 

 on the sides of a flat rachis. 



Species. 1. T. sativum. Cultivated. Of this impor- 

 tant species there are 3 well known varieties, as ec. cestU 

 Tum (Spring-wheat). /3. hijbcmum (autumnal or winter- 

 wheat), y. durum, with the culm solid, and the seed hard, 

 and affbrding but little farina. This worthless variety is 

 the only one cultivated throughout Barbary. The native 

 place of this species, as well as the T. polonicum and T. 

 Spelta, can now no longer be ascertained; still it appears 

 probable that the T.sativiwi originated in Egypt, the era- 



