104 Class V. Order II. 



base ; horns erect incurved. Mass of anthers greenish, as long; 

 as the nectaries; stigma whitish. Flowers purple. July.- 

 Perennial. 



The bark is very strong and fibrous. 



ASCLEPIAS QUADRIFOLIA. Four leaved rfsclepias. 



Stem erect, simple, smooth ; leaves ovate, acumi- 

 nate, petioled, the middle ones in fours ; umbels few, 

 lax, filiform. 



A delicate species growing in dry woods. Stem about a foot 

 high, smooth or slightly pubescent. Leaves in fours, slightly 

 petioled, ovate, acute, paler underneath. The upper and lower 

 ones are most frequently opposite. Umbels few, axillary and ter- 

 minal. Petals flesh coloured. Nectaries nearly white with the 

 horns curved inward. Roxbury, Brookline. June. Perenni- , 

 aJ. 



ASCLEPIAS VERTICILLATA, L. Whorl edvlsclepias. 



Leaves revolute, linear, whorled ; stem erect. L. 



This very neat species is altogether different in its habit from 

 those already described. Stem slender, marked with downy 

 stripes. Leaves in whorls of five or six, linear, revolute at the 

 margin, paler beneath. Umbels several, small, coming out from 

 among the upper whorls. Corolla greenish with a central trans- 

 parent line. Nectaries white, scarcely half as long as their 

 horns, auriculated at base inside, concavely truncate, with an 

 acuminate tooth each side the fissure within. Horns arching 

 and meeting at a distance from the stigma. On a hill near the 

 Dedham turnpike, Roxbury. July. Perennial. 



Subgenus ACERATES. Horn of the nectary wanting* 

 ASCLEPIAS VIRIDIFLORA. Pursh. Green flowered Asclepias. 



Stem simple, erect, hairy ; leaves oblong, subses- 

 sile, downy on both sides ; umbels lateral, solitary, 

 subsessile, nodding, dense and globose ; horn wanting. 



An inelegant species with small greenish umbels. In Leices- 

 ter, Massachusetts. In New-Haven, Dr. Ives. July. 



