732 EXPLANATION OF THE PLATES. 



BRACHYELYTRTJM. — A spikelet of B. aristatum enlarged (1) ; the same displayed (2). 

 CALAMAGROSTIS. — An open spikelet of C. Canadensis, enlarged, displaying all the parts (1) ; 



the same with the flower raised out of the glumes, showing the hairy rudiment behind 



the upper palea (2). 



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

 removed from the glumes (2). Notice the remarkably long squamulae or hypogynous 

 scales, which here nearly equal the paleae in length. 



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



ARISTIDA. — A spikelet of A. purpurascens, enlarged. 



Tab. III. 



SPARTIN A. — Portion of the inflorescence of S. stricta, of the natural size (1) ; a spikelet en- 

 larged (2) ; and the same displayed, the flower raised above the glumes (3). 



CTENIUM. — Spike of C. Americanum (1) ; a single spikelet magnified (2) ; and the same dis- 

 played, the glumes separated (3). 



BOUTELOUA. — A portion of the compound spike, of the natural size (1) ; and a spikelet dis- 

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



GYMNOPOGON. —Inflorescence of G. racemosus, reduced in size (1) ; and a magnified spikelet 

 with the parts displayed (2). 



CYNODON. — Inflorescence, of digitate spikes (1 ; a spikelet magnified and displayed, show- 

 ing a perfect flower and a rudiment (2). 



DACTYLOCTENIUM.- Inflorescence of D. jEgyptiacum, of digitate spikes (1); one of the 

 spikelets magnified (2) ; the fruit magnified (3), showing the seed loose in the thin peri- 

 carp (utricle) ; and (4) the wrinkled seed more magnified. 



ELEUSINE. —One of the spikes from the digitate inflorescence of E. Indica (1) ; a magnified 

 spikelet (2) ; the same with the flowers more displayed (3) ; a flower from the last show- 

 ing its parts (4) ; the fruit magnified, showing the seed loose in the utricle (5) ; and the 

 wrinkled seed detached (6). 



LEPTOCHLOA. — Small portion of the inflorescence of L. fascicularis (1) ; one of its spikelets 

 displayed and magnified (2; ; an open flower of the same (3). 



Tab. IV. 



TRICUSPIS.— Magnified spikelet of T. seslerioides (1); the same displayed and the lowest 

 flower open (2) ; back view of the lower paleae spread out (3). 



DUPONTIA, or, as it should be, GRAPHEPHORUM (see Addenda, p. a). — A magnified spike- 

 let of Dupontia Cooleyi or Graphephorum melicoides, displayed (1) ; a part of the hairy 

 rhachis and one flower of the same (2). 



DIARRHENA. — A spikelet of D. Americana, enlarged (1) : the grain and paleae (2). 



DACTYLIS. — A spikelet of D. glomerata magnified and displayed. 



KCELERIA. — A magnified spikelet of K. cristata, expanded, showing the glumes, the three 

 flowers, and a rudiment (1) ; lower half of a lower palea, partly spread open (2) ; it is 

 much more folded and keeled in its natural condition. 



EATONIA. — A magnified spikelet of E. obtusata, expanded, showing the glumes, the two flow- 

 ers, and a rudiment. 



