284 TRANS. OP THE ACAD. OP SCIENCE. 



secondary ribs connected with the midrib, while in Nymphma 

 most ribs are basilar, and few only come from the midrib. 



The flowers of our plant emerge a few inches above the 

 surface of the water ; they are the largest of any known 

 Nuphar, and are composed of from 9 to 12 sepals, many 

 more than we find in any other species, whence the name. 

 The sepals being concave, and " the inner ones curved in, 

 partially concealing the greater part of the dense mass of 

 stamens," the flower becomes " globular cup shaped," and 

 is about 3 inches in diameter, while when fully laid open it 

 measures 4^-5 inches. The sepals are arranged, not, as it 

 was at first supposed, in 3 or 4 whorls of 3 sepals each, but 

 in T 5 3 disposition, or, perhaps, the outer ones in | divergence, 

 gradually changing into T %. The sepals increase in size and 

 petaloid appearance from the outermost or first to the 7th or 

 8th, when they decrease again in size, but become of more 

 delicate petaloid structure and color ; the three outer ones 

 are oval, l\-l% inches long, green with yellowish margins ; 

 the 2 or 3 next ones are orbicular, 2-2Unches long, and of a 

 yellowish green color; the following ones are the largest, 1\ 

 inches long, 3 inches in diameter, transverse in shape, broad- 

 ly spatulate at base and retuse or truncate above ; they are 

 yellow, and often "tinged with the red of a deep peach 

 blush, especially in fading;" and the innermost are smaller 

 again, spatulate-orbicular, often emarginate, 1-1^ inches long, 

 yellow, or, especially on the edges, reddish brown. Dr. 

 Parry has repeatedly observed transitions between these 

 inner sepals and the petals. 



The petals themselves are spatulate, truncate, 12-18 in 

 number, "9 lines long and 6 lines broad ;" in the dried speci- 

 mens I find them only 5 lines long and from 2 to 4 lines 

 wide; in Dr. Parry's specimens they are "deep red in the 

 middle and yellow at the base and tip." 



The stamens, much more numerous than in the allied spe- 

 cies, together with the anthers and the appendage, are deep 

 red, relieved by the bright yellow color of the (oval, hispid, 

 as in the genus) pollen, the outer ones broader and shorter, 

 the inner ones narrower and longer ; at maturity they are 

 recurved. 



The stigmatic disc is deeply umbilicate, and bears 13-21 

 (usually 16-19) stigmatic rays, which extend near to the 

 irregularly crenate margin ; 'it has a green or a deep red 

 color or red, edged with yellow, and has, in the dried speci- 

 mens before me, a diameter of 9-11 lines. In N. luteum 

 the disc is similarly formed, while in all the western speci- 

 mens of N. aclvena (I have no others at my disposal) I inva- 

 riably find the disc entire or undulate, and the rays not ex- 

 tending to the margin. 



The fruit found by Dr. Parry, only half ripe, is " smooth, 



