EXPLANATION OF THE PLATES. G99 



LOLIUM. — Portion of the spike of L. temulentum (1); and a separate flower mag- 

 nified (2). b 



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



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

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



H. jubatum, with their ^awn-like glumes, the lateral flowers abortive and 



neutral the middle one alone perfect (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). 



GYMXOSTICHUM. — A spikelet of G. Hystrix (1), and an 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). 



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

 flower from the same (3). 



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

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



AYENA. — 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 

 awned (2). 



Tab. Xm. 



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). 



AXTHOXAXTHUM. — 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. effusum (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). 



PASPALUM — Inflorescence of P. laeve (1); a closed spikelet, enlarged (2); the 

 same with the parts displayed (3). 



PAXICUM. — 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, magnified (4), and 

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

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

 of two palets. A spikelet of P. virgatum, magnified (8); 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). 



