EXPLANATION OP THE PLATES. 697 



Genera of Gramineae or Grasses. 



Tab. VII. 



LEEESIA. — Panicle of L. oryzoides, reduced in size (1); a branchlet of the same 

 witli its spikelets, of ttie natural size (2); and an open spilcelet in flower, en- 

 larged (3). 



ZIZANIA. — A staminate (1) and a pistillate (2) flower or spilcelet of Z. aquatica; 

 a magnified pistil with a pair of squamulse or hypogynous scales (3); a grain 

 (4) ; and a magnified longitudinal section of the lower part of the same, show- 

 ing the embryo at the outside of the base of the albumen. 



ALOPECURUS. — Part of a plant of A. geniculatns, 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 palet detached (4). 



PHLEUM. — A detached spikelet of P. prateose, having the flower with its palets 



raised above the glumes, magnified. 

 CKYPSIS. — Inflorescence (1) of 0. schoenoides; a separate enlarged spikelet (2); 



and the same open, in flower (3). 

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



SPOROBOLUS. — A spikelet of S. cryptandrus, magnified (1)) the same with the 

 flower open, the palets raised above the glumes, (2); and' the fruit (3), more 

 magnified, showing the seed loose in the pericarp (utricle). 



AGEOSTIS. — 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 palet. 



Tab. Vni. 



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



detached spikelet, showing the long awns to the glumes (2); the same open 

 in flower (3); and a separate flower without the glumes (4). 



CINNA. — A magnified spikelet of C. arundinacea (1) ; and the same open, display- 

 ing the paKts, the single stamen, and the pistil (2). 



MUHLENBERGIA. — A magnified closed spikelet of M. sylvatica (1); the same 

 with the open flower raised out of the glumes (2). A magnified spikelet of 

 M. difiusa (3); its minute and unequal glumes more magnified (4); and an 

 open spikelet of the same (B). 



BEACHYELYTKUM. — A spikelet of B. aristatum enlarged (1); the same dis- 

 played (2). 



CALAMAGROSTIS. — An open spikelet of d. Canadensis, enlarged, displaying all 

 the parts (1); the same with the flower raised out of the glumes, showing the 

 hairy rudiment behind the upper palet (2). 



OEYZOPSIS. — An open magnified spikelet of 0. asperifolia (1) ; and the flower of 

 the same removed from the glumeS (2). Notice the remarkably long squa- 

 mulee or hypogyttous scales, which here nearly equal the palets in length. 

 STIPA. — Glumes and fiower (a little separated) of S. avenacea, enlarged. 

 AEISTIDA. — A spikelet of A. purpm-ascens, enlarged. 



• 

 Tab. IX. 



SPARTINA. — Portion of the inflorescence of S. sfriota, of the natural size (1); a 



spikelet enlarged (2) ; and the same displayed, the flower raised above the 



glumes (8). 

 CTENIUM. — Spike of C. Atnericauura (1); a single spikelet magnified (2); and the 



same displayed, the glumes separated (3). 

 BOUTELOUA. — A portion' of the compound spike, of^he natural size (1); and a 



spikelet displayed and magnified (2), the flowers raised out of the glumes. 



