144 PROCEEDINGS OF THE AMERICAN ACADEMY. 
later by C. H. Schultz.’ In 1858 Mueller? collated briefly nine species 
of Zexmenia, not including those previously referred to Lipochaeta. 
At the time of Bentham and Hooker’s Genera Plantarum Zexmenia 
had been extended to include about twenty-five species, and was divided 
into three sections: Wedeliovdes, Lipochaeta, and Lasianthaea. In the 
present treatment the achenial characters alone have been made the basis 
of the sectional division, and it has seemed undesirable to maintain Lipo- 
chaeta and Lasianthaea as sections of the genus, for their species are 
often so nearly alike habitally that it is difficult to distinguish them, 
and in respect to the achenial characters these two sections form a very 
homogeneous group, which may be ver y fitly regarded as Zexmenia proper 
as by Hoffmann? (Huzexmenia). In this portion of the genus the achenes 
are all strongly angled, triangular in the ray-flowers, and much flattened 
(except in Z Salvinii) in the disk-flowers. True wings (developing 
after anthesis) are never present, but the angles are often produced into 
wing-like longitudinally striate margins. The awns are generally longer 
in the disk-achenes than in the ray-achenes. In the former they 
frequently exceed the length of the body of the achene, although they 
are sometimes quite short. On the ray-achenes they are sometimes re- 
duced to short stoutish teeth. When the intermediate pappus scales (squa- 
mellae) are developed to the length of 1 mm. they are always united to 
form a small cup or short tube at the summit of the achene. The entire 
pappus is continuous with the margins of the achene, there being no con- 
striction or pappus-disk at the summit, as will be found in Auchenocarpa, 
to be described later. The inflorescence is of a terminal cymose 
character, but often appears umbellate or fasciculate by a shortening of 
the internodes. In a few species peduncles arise from several of the 
upper nodes. This section includes about twenty-five species 
The § Wedelioides, proposed by Bentham and Hooker, f.4 was 5 used by 
its authors to include an obvious mixture of plants not very nearly re- 
lated. The name was probably suggested by the Wedelia-like habit of 
such species as Z. reticulata, Z. caracasana, and Z. helianthoides, Benth. 
& Hook. f., which can no longer be referred to Zermenia. Wedelioides 
as a section of Zexmenia would, therefore, better be abandoned. The 
portion of the § Wedelioides, Benth. & Hook. f., which it seems best to 
retain in Zeamenia, together with several more recently described species, 
eStats abo ee een bon wr Se 2 
1 Sch. Bip. in Seem. Bot. Voy. Herald, 305-806. 
2 Mueller in Walp. Ann. vy. 225-226. 
® Hoffm. in Engl. & Prantl. Nat. Pflanzenf. iv. Ab. 5, 238. 
* Gen. ii. 373 (1873). 
