592 ORDER CXLII. GRAMINACE.E. 



Genus XXXIV.— UNIO'LA. L. 

 (The ancient name of some grass.) 



Glumes lanceolate, compressed, keeled. Florets 3 — 20, in 

 two rows. Spikelets compressed ; the lower palea carinate, 

 mucronate, the upper one subulate. Scales emarginate. Seed 

 2-horned. 



1. XJ. latifo'lia, (Mich.) Stem terete, glabrous. Leaves flat, gla 

 brous; throat of the sheath ciliate. Glumes 3, 7 — 14-flowered, tin 

 upper ones sterile ; exterior palea many-nerved, with the keel ciliate 

 Flowers generally monandrous. — If. Aug. — Sept. Mountains. 



2. U. nit'ida, (Bald.) Stem glabrous. Leaves flat, narrow. Pant 

 cles expanding, few-flowered. Glumes 3, many-flowered. Flowers mo- 

 nandrous. — IX. June — July. Middle Geo. 2 — 5 feet. 



3. XJ. panicula'ta, (L.) Stem erect, glabrous. Leaves long, narrow, 

 entire, glabrous ; sheaths hairy at the throat. Panicle large. Glumes 

 4 — 5, many-flowered ; exterior palea mucronate, 6-nerved, interior one 

 ciliate. — IX. July — Aug. On the sea-coast. 4 — 8 feet. 



4. XJ. gra'cilis, (Mich.) Stem glabrous, erect. Leaves scabrous on 

 the upper surface, linear, flat. Glumes 3, 3-flowered. Panicle long, 

 erect, with appressed branches. Flowers monandrous. — If. Through 

 the summer. Very common. 1 — 2 feet. 



Genus XXXV— ARXJNDINA'RIA. Rich. 

 (From arundo, a reed.) 



Glumes 2, many-flowered, unequal, the exterior one smallest. 

 Palea? 2, unequal, the exterior one largest. Styles 3-cleft, short. 



1. A. macrosper'ma, (Mich.) Stem erect, glabrous, terete, with hollow 

 internodes. Leaves large, flat, distichous ; sheaths longer than the joints. 

 Panicle terminal, composed of distichous spikes ; peduncles pubescent ; 

 the exterior glumes ciliate, very small ; the exterior palea largest, cili- 

 ate. Seed cylindrical. Does not flower every year; when it does 

 bloom, it is in the spring. — If. Rich damp soils. 5 — 20 ft. Cane. 



Genus XXXVL— TRIT'ICXJM. L. (Wheat.) 

 (From tritum, ground ; because the fruit is ground.) 



Flowers in spikes ; spikelets distichously imbricate, sessile, 

 3 — 4 -flowered. Glumes 2, nearly equal, opposite. Palecehm- 

 ceolate ; the lower concave, acuminate or awned. Scales 2, 

 ciliate. 



1. T. sati'vum. Spikes 4-angled, imbricated ; spikelets 4 or less ; 

 valves ventricose, ovate, truncate, mucronate ; nerve prominent. Flow- 

 ers awned or unawned. Fruit free. 



The native country of wheat is uncertain, al hough it has been thought to have 

 been indigenous to Central or Southwestern Asia. It has been cultivated for thou- 

 sands of years. There are now no less than three hundred varieties in cultivation. 

 The character of the grain is very much aifected by soil and culture : the richest soil 

 and highest culture produce the richest grain. 



Secale ccrecrfe, liye, is native among the mountains of Caucasus, around the Cas- 

 pian Sea, and in the Crimea. 



