734 EXPLANATION OF THE PLATES. 



ARRENATHERUM. — A spikelet of A. avenaceum displayed and magnified : 1, the glumes ; 

 2, the flowers, the lower one staminate only, the next perfect, and the third a rudiment. 



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

 flowers, the lower one perfect and awuless, the upper staminate and awned (2). 



Tab. VII. 



HTEROCHLOA. — 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 stamens (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 palea, the middle one perfect and diandrous (3). 



PHALARIS. — A spikelet of P. arundinacea enlarged (1) ; the glumes and the perfect flower 

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



MILIUM. — Portion of the panicle of M. effusum (1) ; a closed spikelet magnified (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, enlarged (3). 



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

 the parts displayed (3). 



PANICUM. — 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 palea. A spikelet of P. capillare, magnified (4), and the same displayed (5) : 

 the lower flower a single palea. A spikelet of P. clandestiuum, magnified (6), and the 

 same displayed (7) : the lower flower neutral, of two paleae. A spikelet of P. virgatum, 

 magnified (8) ; the same displayed (9) : the lower flower of two palese and staminate. 



SETARIA. — A magnified spikelet of S. glauca, with the accompanying cluster of bristles (1) ; 

 the spikelet displayed, showing the neutral lower flower of two paleae and the perfect 

 flower (2). 



Tab. VIII. 



CENCHRUS. — A spiny involucre of C. tribuloides, in flower, enlarged (1) ; longitudinal sec- 

 tion of the same (2) ; a spikelet detached and displayed (3) : the stigmas should belong 

 to the right-hand or upper flower ; the lefUhand or lower flower is only staminate. 



TRIPSACUM. — Piece of the spike v of the natural size), pistillate below, staminate above (1) ; 

 a longitudinal section of one of the pistillate spikelets (2) ; a pistillate spikelet with its 

 parts displayed (3) ; a staminate (2-flowered) spikelet, with its parts displayed (4). 



ERIANTHUS.— Part of the hairy inflorescence with two spikelets of E. alopecuroides, en- 

 larged (1) ; one of the spikelets displayed (2). 



ANDROPOGON.— Small portion of the spike of A. furcatus, enlarged, with one fertile and 

 awned spikelet, and one staminate and awnless spikelet (1) ; the fertile spikelet (2), and 

 the staminate spikelet (3) displayed. 



SORGHTJM. — A fertile spikelet of S. nutans, enlarged, with a sterile pedicel on each side (1) ; 

 the spikelet displayed (2). 



