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. 



Beturning now to Thyrsanthema, I note first of all that a 

 highly significant name is assigned this new genns ; even a 

 diagnostic one. It gives distinct intimation of the nature of 

 the inflorescence. Thyrsanthema — 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 Thyrsanthema 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 Thyrsanthema 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 tliese 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 

 acaulesceut species, a group with monocephalous or monanthous 

 scapes he would treat as forming a genus disDinct 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 those on page 7 another. Or more taxonomically, 

 to Atasites and 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 thyrsifiorus scapes, between 

 two others, each of which have monanthous scapes. This is a 

 very essential item in the Neckerian taxonomy. 



Let us now compare diligently the descriptions Necker gives 

 of these two allied genera Thyrsanthema and Petasites, The 



