Tnhcum.] GRAMINEjE. 315 



25. Triticum. Linn. Wheat or Wheat-grass. 



Calyx 2-valved, many-flowered ; its valves opposite, trans- 

 verse, the sides (not the back of one of them) directed to 

 the rachis, nearly equal. Corolla 2-valved, valves lanceolate ; 

 exterior one acuminate or awned at the extremity, interior 

 bifid at the point. — There are two natural groups in this 

 genus: first, the large annual species, exotic to our country, 

 which are cultivated so extensively as Bread-corn; and, 

 secondly, the smaller perennial species, several of which are 

 natives with us. These, some authors look upon as two dis- 

 tinct genera; Triticum and Agropyrum, ( Beauv., Lindl.J 

 We have only to consider the latter genus, or group. — Name, 

 Triticum, " quod tritum est e spicis :" because it is thrashed 

 or beaten from the spikes. 



Triandria. Digynia. 



•%. Spikelets distichous. 



1. T. canimim, Huds. Fibrous-rooted Wheat-grass. Calyx- 

 awn valved, with 3 — 5 ribs, and about five awned florets ; leaves 

 plane; root fibrous. Br. Fl. ed. 3. p. 56. E. Fl. v. i. p. 184. 

 E. Sot. t. 1327. — Elyrmts can., Linn. 



Woods and hedges. Plentiful at Woodlands, County of Dublin. 

 Fl. July. %. — Best distinguished from the following by its fibrous 

 root. 



2. T. repens, Linn. Creeping Wlieat-grass or Couch-grass. 

 Calyx-valves many-ribbed, with from 4 — 8-awned (rarely awn- 

 less) florets ; leaves plane; root creeping. Br. Fl. ed. 3. p. 56. 

 E. Fl. v. i. p. 182. E. Bot. t. 909. 



Fields and waste places, abundant. Fl. throughout the summer 

 months. %.• — In habit between the preceding and the following, 

 having a glaucous tint when growing near the sea. Leaves plane, or 

 nearly so. Spikelets smaller and less compressed than in T.junceum. 

 — This pest of the corn-fields is difficult to be extirpated, on account 

 of its long creeping roots. 



3. T. junceum, Linn. Rushy Sea Wheat-grass. Valves of 

 the calyx obtuse, much ribbed, with 4 — 5 awnless florets ; leaves 

 involute, pungent ; root creeping. Br. Fl. ed. 3. p. 56. E. 

 Bot. t. 814. E. Fl. v. i. p. 182. 



Sandy sea-shores, frequent. Fl. July. % . — Whole plant glaucous, 

 rigid. One and a half to three feet high. Spike long. Spikelets ob- 

 long, much compressed, distant, sessile. Calyx-values oblongo-lan- 

 ceolate, often with three teeth at the point. Exterior valves of the 

 corolla similar, with five nerves. 



* * Spikelets secnnd. 



4. T. loliaceunif Sm. Dwarf Sea Wheat-grass. Valves of 



