71 



Pappus of disc-achenes consisting of twelve or fewer linear paleae, 

 each narrowly margined on each side with a hyaline striate 

 fringe, which is very minutely denticulate on the edge, and 

 toward the apex of the palea becomes largely modified into a 

 very minute ciliation. The first impression one gets on exam- 

 ining this structure is that the palea is densely ciliate through- 

 out, but for the greater part the elements are united nearly to 

 the apex (fig. B). 



Disc-corollas with a long slender basal tube, the extreme base of 

 which is swollen (fig. F). 



Ray-corollas with a long slender basal tube; pistil present, the 

 style branches straight and rather long (fig. D) ; on the wall of 



^\ 



. \^ 



i-ai. F. 



m o. 



Fig. I. Helianthoid genus Tonalanlhus. For description of figures see text. 



the corolla, behind the style branches, are two linear or nar- 

 rowly strap-shaped processes (fig. £), the function of which is 

 not evident. They do not extend down the tube, but are 

 attached to the base of the ray. 

 This has to be referred to the Heliantheae rather than the Helen- 

 ieae on account of the chaffy bracts of the receptacle, and aside 

 from this character it does not closely resemble any genus of 

 Helenieae. The afifinity appears to be with the Galinsoginae, an 

 apparently ancient group containing a number of American and 

 two Hawaiian genera. The pappus of Tridax procumhens L. 

 seems to show a further development of exactly the same feature 

 as are found in Tonalanlhus, while the disc-corollas have some of 

 the characters of Marshallia. 



T. D. A. COCKERELL. 



