156 LEAFLETS. 
own reiterated statement, some Linnaean Tussilago is its type ; 
to which type Arnica Gerbera, Linn., is appended, as it were to 
get it out of the way. 
Returning now to Zhyrsanthema, I note first of all that a 
highly significant name is assigned this new genus; even a 
diagnostic one. It gives distinct intimation of the nature of 
the inflorescence. Zhyrsanthema—thyrsoidly arranged flowers— 
will apply to none of those species of the Linnaean Tussilago 
the scapes of which are monocephalous; and so it is definitely 
indicated by the very name, that 7hyrsanthema is not Tussilago 
nutans, Linn. It would apply well enough to all those species 
of the old genus Petasites which Linnaeus reduced to Tussilago. 
I therefore judge by the name alone, without even a glance at 
the Neckerian diagnosis, that we have in Zhyrsanthema some 
segregate of Petasites, the genus one of the characters of which 
is a thyrsiform inflorescence. Indeed, I feel quite sure of it; 
and a glance at what Necker has to say of the inflorescences of 
each of these four proposed segregate genera makes me doubly 
sure. I know beforehand that this author was accustomed to 
reckon as of generic value such distinctions as those between 
acaulescent and caulescent allies; and when it came to the 
acaulescent species, a group with monocephalous or monanthous 
scapes he would treat as forming a genus distinct from one with 
polycephalous or polyanthous scapes. I learned this part of 
Necker’s method long ago. And, assuming that he was ruled by 
it in the present case, the two genera on his page 6 form 
one group, and thoseon page 7 another. Or more taxonomically, 
to Afasitesand Tussilago on page 7 are ascribed monocephalous 
scapes. Of the two on page 6, the last we know to be polyceph- 
alous, hence, even if Thysanthema had been given a meaningless 
name, we should feel confident that it had a polycephalous scape, 
because of our knowledge that this author did never such a 
thing as to intercalate a genus with thyrsiflorus scapes, between 
two others, each of which have monanthous scapes. This is a 
very essential item in the Neckérian taxonomy. 
Let us now compare diligently the descriptions Necker gives 
of these two allied genera Zhyrsanthema and Petasites. The 
