﻿Studies in the Asclepiadaceae. — II. 



By Anna Murray Vail. 



I— A REVISION OF THE GENUS ACERATES IN THE UNITED STATES. 



The genus Acerates was first established by Elliott, in 1817, 

 and based on the species now known under the name of Acerates 

 Floridana (Lam.) Hitchcock, but the author doubts at the same 

 time whether the absence of the horn-like appendage constitutes 

 a sufficient character to separate it from Asclepias. 



In 1834 Nuttall named the genus Polyotus, claiming that the 

 name Acerates had been already used for another genus and includes 

 in it four species. Rafinesque treated the genus variously in 1836, 

 but altogether too vaguely to be noticed seriously. Since then 

 the species have been transferred from one genus to another. 

 Bentham and Hooker placed them with Anantherix under Gompho- 



ypus 



K 



Family 



Pflajizeiifaniilien, it is i; 

 * Nutt. in the genus Asclepias. 



Dr. Gray, in his several studies of the North American Asclepiads, 

 kept Acerates distinct, which seems in every way the most satis- 

 factory and logical thing to do. The following description of the 

 genus is enlarged to include that anomalous and much discussed 

 species, Asclepias stenophylla, and a new species, Acerates Rusbyi, 

 which seem to be the connecting links between the genera with 

 horned hoods and those with unappendaged hoods. 



ACERATES Elliott, Be 



[Polyotus Nutt. Trans. A 

 [* Oligoron Raf. New Fl 



7 



*Acerotis Raf., 1817, in New Fl. Am. 1:49, 1836, is given as a synonym of 

 Acerates and is there changed to Otanema. In New FL 4 J 60, 1836, Oligoron is 

 also made synonymous with Acerates and includes two species; one of which is prob- 

 ably Acerates Floridana in part ; the other species O. tenuifolium might possibly 

 refer to Acerates auriculata Engelm. The genus Otanema Raf. 1. c. 4: 61, appar- 

 ently refers to forms of Acerates viridiflora. I do not know the 1817 reference to 

 Ac trot is, 



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