EXPLANATION OF THE PLATES. 701 



LOLIUM. — Portion of tlie spike of L. teraulentum (1); and a separate flower, mag- 

 nified (2). 



TRrnCUM.— Portion of the spike of T. repens, or Couch-Grass, of about the 

 iiaturiil size (1); a flower, magnified (2). 



HORDKUM. — The three one-flowered spikelets from one joint of the spike of 

 H. jubiitum, witli tlieir awn-like glumes, the lateral flowers abortive and 

 neutral tlie middle one alone ])erfect (1); this perfect flower (with an awn-like 

 rudiment) open and enlarged (2). 



ELYMUS. — The two spikelets of one joint of the spike of E. Virginicus, about the 

 natural size (1); the glumes and the flowers of one spikelet, enlarged and 

 displayed (2); and an open flower,- more magnified (3). 



GYMNOSTICHUM. — A spikelet of G. Hystrix (1), and au expanded flower, mag- 

 nified (2). 



Tab. XII. 



AIRA. — Panicle of A. flexuosa (1); a spikelet, magnified, the parts displayed (2); 



and one of the flowers detached and open (3). 

 DANTUOXIA. — Panicle of D. spicata (1); a spikelet enlarged (2); and a separate 



flower from the same (3). 

 TRISETUM. — A spikelet of T. subspicatum, var. moUe, expanded and magni- 

 fied (1); and a separate open flower (2). 

 AVENA. — A spikelet of A. striata displayed and magnified (1); and a separate 



flower (2). 

 ARRENATHERUM. — A spikelet of A. avenaceum, displayed and magnified: 



1, the glumes; 2, the flowers, the lower one staminate only, the next one 



perfect, and the third a rudiment. 

 HOLCUS. — A spikelet of H. lanatus magnified (1); the same displayed to show 



the two flowers, the lower one perfect and awnless, the upper staminate and 



awued (2). 



Tab. XIIL 



HIEROCHLOA. — A spikelet of H. borealis, enlarged (1): the same displayed, the 

 flowers separated from the glumes, the two lateral ones with three stamens 

 and no pistil; the middle or terminal one with a pistil and only two stam- 

 ens (2). 



ANTHOXANTHUM.— The spike-like inflorescence of A. odoratum (1); a spikelet 

 magnified (2); another with the parts displayed, the flowers raised from the 

 glumes, the lateral ones neutral, each of a single and awned palet, the middle 

 one perfect and diandrous (3). 



PHALARIS. — A spikelet of P. arundinacea enlarged (1); the glumes, and the per- 

 fect flower with a hairy rudiment on each side of it (2). 



MILIUM. — Portion of the panicle of M. eff"usum (1); a closed spikelet magni- 

 fied (2); and the same displayed (3). 



AMPHICARPUM. — A spikelet from the panicle of A. Purshii, magnified (1); the 

 same with the parts displayed (2); and a radical (fertile) spikelet, en- 

 larged (3). 



P ASP ALUM — Inflorescence of P. Ijsve(l); a closed spikelet, enlarged (2); the 

 same with the parts displayed (3). 



PANICUJL — Part of a spike of P. (Digitaria) sanguinale (1); one of its spikelets 

 magnified (2) : the same with the parts displayed (3): in this the lower flower 

 is neutral and of a single palet. A spikelet of P. capillare, mngnified (4), and 

 the same displayed (5): the lower flower a single palet. A spikelet of P. 

 clandestinutn, magnified (6), and the same displayed (7): the lower neutral, 

 of two |)alets. A spikelet of P. virgatum, magnified (S); the same displayed 

 (9): the lower flower of two palets and staminate. 



SET ARIA. — A magnified spikelet of S. glauca, with the accompanying cluster of 

 . bristles (1); the spikelet displayed, showing the neutral lower flower of two 

 palets and the perfect flower (2). 



