EXPLANATION OF THE PLATES. 



Genera of Gramiiiese, or Grasses* 



TAB. I. 



LEERSIA. Panicle of L. oryzoides, reduced in size (1); a branchlet of the same with its 



spikelets, of the natural size (2) ; and an open spikelet in flower, enlarged (3). 

 ZIZANIA. A staminate (1) and a pistillate (2) flower or spikelet of Z. aquatica , a magnified 



pistil with a pair of squamuke or hypogyrious scales (3) ; a grain (4) ; and a magnified 



longitudinal section of the lower part of the same, showing the embryo at the outside 



of the base of the albumen. 

 ALOPECURUS. Part of a plant of A. geniculatus, in flower (1); a few spikelets from the 



spike-like inflorescence, moderately magnified (2) ; an open spikelet in flower, more 



magnified (3), and the single lower palea detached (4). 

 PHLEUM. One spikelet of P. pratense, having the flower with its palese raised above the 



glumes, magnified. 

 CRYPSIS. Inflorescence (1) of C. schoenoicles (see Addenda, p. xcix.)j a separate enlarged 



spikelet (2) ; and the same open, in flower (3). 



VILFA. An enlarged spikelet of V. vaginseflora (1) 5 and the same displayed (2). 

 SPOROBOLUS. A spikelet of S. cryptandrus, magnified (1) ; the same with the flower open, 



the paleas raised above the glumes (2) ; and the fruit (3), more magnified, showing the 



seed loose in the pericarp (utricle). 

 AGROSTIS. Panicle of A. vulgaris (1) ; with an enlarged open spikelet of the same : also (3) 



the rough pedicel and glumes of A. scabra, with the flower separated, the latter having 



no upper palea. 



TAB. II. 



POLYPOGON. Spike-like contracted panicle of P. Monspeliensis (1) ; an enlarged- detached 

 spikelet, showing the long awns to the glumes (2) 5 the same open in flower (3) ; and a 

 separate flower without the glumes (4). 



CINNA. A magnified spikelet of C. arundinacea (1)-, and the sam open, displaying the 

 palese, the single stamen, and the pistil (2). 



MUHLENBERGIA. A magnified closed spikelet of M. sylvatlca (1) ; the same with the open 

 flower raised out of the glumes (2). A magnified spikelet of M. diffusa (3) ; its minute 

 and unequal glumes more magnified (4) ; and an open spikelet of the same (5). 



