52 Contributions from the Gray Herbarium 
ZEXMENIA guaranitica (Chod.), comb. nov. — Verbesina guara- 
nitica Chod. ! Bull. Herb. Boiss. ser. 2, iii. 722 (1903). — Careful 
study of the type numbers (Hassler 5647 and 8132, in the British 
Museum) of this Paraguayan species has led me to make this 
transfer. The achene, narrowly winged on both edges with the 
wing expanded above on one edge somewhat in the manner of an 
Otopappus, bears a pappus of two awns connected by a distinct 
although short corona of basally fused squamellae. For this rea- 
son the species can not be included in Verbesina. Its inclusion 
with the two following species in Zexmenia necessitates a slight 
change in the generally accepted character of that genus, since 
the leaves in all three species are at least in part alternate. In 
none of the three has the base of the stem been seen, but in Z. 
guaranitica and Z. myrtifolia all the leaves on the upper foot or 
two of the stem, at least, are alternate; in Z. paraguariensis the 
lower leaves of the incomplete specimen examined are opposite, 
the upper alternate. Although the possession of opposite leaves 
has generally been more or less emphasized as a characteristic 
feature of Zexmenia, there is at least one other species whose place 
in the genus has never been questioned, Z. brevifolia Gray, im 
which also alternate leaves are found, at least on the branches — 
a fact long ago noted by Dr. Gray. 
ZEXMENIA myrtifolia (Chod.), comb. nov. — Verbesina myrti- 
folia Chod.! Bull. Herb. Boiss. ser. 2, ii. 393 (1902). — A good 
Zexmenia, but like the last somewhat anomalous in its alternate 
leaves. The rather young achene is narrowly winged on both 
edges, the wings continuous with the stout awns, and one awn is 
obliquely decurrent by a broad denticulate base into the other, 
this broad base representing a somewhat peculiarly developed 
_ Squamellaceous crown. When dissecting flowers of Hassler 4991, 
the type collection, at the British Museum, I found that the style- 
branches of the ray bore a distinct subulate-acicular appendage, 
about as long as that of the disk-flowers, from which they differed 
only in being nearly glabrous throughout. The occurrence on the 
style-arms of the ray-florets of this appendage, so commonly 
found on those of the disk in genera of this group of the Compost- 
tae, is decidedly unusual. 
ZEXMENIA paraguariensis (Chod.), comb. nov. — Verbesina 
paraguariensis Chod. ! Bull. Herb. Boiss. ser. 2, iii. 722 (1903). — 
