GLEASON: TAXONOMIC STUDIES IN VERNONIA 251 
Oliganthes Milleri (Johnston) comb. nov. 
Vernonia Milleri Johnston, Proc. Am. Acad. 11: 698. 1905. 
The structure of the pappus of this little-known species from 
the island of Margarita indicates clearly its affinity with Oligan-_ 
thes rather than with Vernonia. 
Piptocoma rufescens latifolia var. nov. 
Leaf-blade narrowly ovate or elliptic, two to three times as 
long as wide, broadly obtuse or rounded at the apex, abruptly 
narrowed at the base, its tomentum loose and thin; petiole 1 cm. 
long; involucre larger and its scales more tomentose than in the 
typical form of the species. 
Type: Britton, Britton & Shafer 104, from a coastal thicket on 
Water Island, St. Thomas, January 31 to February 4, 1913, and 
deposited in the herbarium of the New York Botanical Garden; 
a second sheet in the same collection is Britton & Shafer 845, from 
a coastal thicket on Salt Island, Tortola. 
The species of Elephantopus occurring in the southeastern 
United States have long been a difficult problem for taxonomists. 
E. carolinianus Willd. and E. nudatus Gray are quite distinct 
and have generally been recognized. Gray, in the Synoptical 
Flora, in 1886, combined E. tomentosus L. with E. elatus Bertol., 
and in general Bertolini’s species was not recognized until 1901. 
Baker then regarded it as distinct and gave some valuable com- 
parative measurements. While the difference in length of in- 
volucral scales and pappus is distinct in mature heads, it is not 
always reliable at earlier stages. Possibly for this reason, Baker’s 
measurements have been neglected by recent authors, and Small 
has separated the two species chiefly on characters of leaf and 
pubescence, which are unfortunately exceedingly variable. 
One diagnostic character has however been overlooked. In 
E. tomentosus the hairs on the midvein are generally reflexed, while 
on the leaf-surface proper many or all of the hairs point backward. 
In E. elatus the hairs of the midvein are longer and stiffer and 
point distinctly forward. Separated by this character, many 
specimens usually referred to E. tomentosus are found to belong 
to the other species, having also the short, heavily invested scales 
