CONTRIBUTIONS FROM THE GRAY HERBARIUM OF HARVARD 
UNIVERSITY, NEW SERIES.—No, XXX 
A REVISION OF THE GENUS ZEXMENIA. 
By W. W. Jonss. 
Presented April 12, 1905. Received May 8, 1905. 
Tae genus Zermenia, belonging to the helianthoid Compositae and re- 
stricted to tropical and subtropical America, was originally described by 
La Llave and Lexarza' in 1824 and founded upon a single Mexican 
Species, Z. serrata. The name Zexmenia was not taken up by De 
Candolle in his Prodromus, nor by his immediate successors in cosmo- 
politan classification, as, for instance, Endlicher (Gen. PJ. 1838) and 
Steudel (Nomencl. Bot. 1840). This neglect was doubtless due to the 
fact that La Llave’s plant had not been rediscovered and the type, even 
if preserved, had not been seen by any of these authors. It is probable 
from a reference by D. Don? that La Llave sent him a specimen of his 
Z. serrata, but even if that were the case, it was probably deposited in the 
great Lambert Herbarium, which was sold in sections, and it would now 
be difficult if not impossible to trace the specimen in question. 
In the Prodromus, v. 610, De Candolle described under the name 
Lipochaeta a genus of nine species, five of which came from the Sand- 
wich Islands and the remaining four from Mexico, La Llave’s Zermenia 
serrata being added as doubtfully belonging to this genus. 
In 1852 Gray* restored the name Zexmenia, not only for its still an- 
known type, but for Lipochaeta strigosa, DC., and several of his own new 
species. Gray states that these are not congeneric with De Candolle’s 
Hawaiian species, to which, in his opinion, the name Lipochaeta should be 
restricted. He also refers Lasianthaea helianthoides, DC. to Zexmenia 
and makes it the basis of the sectional group Lasianthaea, later taken up 
by Bentham and Hooker, f. Gray, however, did not transfer specifically 
the five American species of Lipochaeta to Zexmenia, but this was done 
1 Nov. Veg. Desc. fase. i. 13. 2 Trans. Linn. Soc. xvi. 170. 
3 Pl. Wright. i. 113. 
