252 Asclepias* — Diplocea Barhatct, 



Art. VII. ' Description of a new species of Asclepias. Bif 

 Dr. Eli Ives, Professor, «^c. in the Medical Institution 

 of Yale College. {With a Plate.) 



JL HE plant, which is the subject of the following observa- 

 tions, is found growing abundantly on the sandy plains east of 

 Cedar Hill, in New-Haven. It is locally associated with the 

 asclepias viridiflora and verticillata. When this species of 

 asclepias was first noticed by me, it was supposed to be a 

 variety of viridiflora of Rafinesque and Pursh ; but after ex- 

 amining a great number of specimens, it was found that the 

 varieties did not blend themselves. The leaves of the viridi- 

 flora being uniformly oblong and obtuse, the leaves of the 

 other uniformly lanceolate and acute. To this new species I 

 purpose to give the name Lanceolata. 



Specif c character of the asclepias lanceolata : — Stem de- 

 cumbent, hirsute ; leaves opposite, lanceolate, acute, .sub ses- 

 sile, hirsuit umbels lateral, solitary, sessile, nodding, subglo- 

 bose, dense-flowered ; appendage none. See the plate. 



The asclepias lanceolata is allied to the asclepias longifolia 

 and viridiflora by the absence of appendage or horn of the 

 nectary. It is distinguished from the longifolia, which is 

 characterized by alternate linear leaves, and umbels erect. 



The asclepias lanceolata and asclepias viridiflora belong 

 to Mr. Elliott's genus acerates. In both, the nectary or 

 stamineous crown is short concave, and oppressed to the 

 angles of the filaments. 



Art. VIII. Description of a JVew Genus of American 

 Grass. Diplocea Barbata, by C. S. Rafinesque, Esq. 



X_yIPLOCEA. Generic definition. Flowers paniculated mo- 

 noical or polygamous. Exterior glumes membranaceous bi- 

 valve one to three flowered, valves subequal emarginated 

 mutic. Anterior glumes bivalve unequal, the largei^it notched, 



