ATASITES AND THYRSANTHEMA, 157 
distinguishing mark between them is one only. In the former 
the bracts of the involucre are in several series and imbricated. 
In the latter they form but a single series, are equal and not 
imbricated. It is such a distinction as the most accomplished 
synantherologists of a hundred years past and more, have 
recognized as of generic value. 
Now, whoever shall find among the thyrsiflorous species of 
Linnaean Tussilago, one that has imbricated involucral bracts, 
will have the type of Zhyrsanthema, Neck. 
I regret the necessity of here indicating how reckless the 
author of the Revisio @enerum has been in his reading of 
Necker upon Zhyrsanthema. The name, first of all, has been 
meaningless to him. He cannot have given it a thought. He 
‘assumes that to be scapose, a plant must have monocepha- 
lous scapes. Had he read the corresponding part of the diag- 
nosis of Petasites he would have discovered this error; for 
Necker says of that also, proles scaposae, indicating no differ- 
ence. Necker is made to say of the ray flowers that they are 
small (parvi), which would apply well enough to those of Chag- 
latia, but Necker says those of 7hyrsanthema are minute. That 
is not parvi; and the term minuti while not applicable to the 
outer circle of corollas in Chaptalia is true to the letter in those 
of certain Linnaean thyrsoid Tussilago species. Necker says of 
the pappus of his genus, simplex pilosusve, which in the Revisio 
is put down as simplex pilosus. One means simple or pilose, 
the other simple and pilose. I do not comprehend the force of 
this part of Necker’s diagnosis; but I do know that simplex 
pilosusve is not the same in meaning as simplex pilosus. 
As regards Chaptalia, based as it is on Tussilago nutans, it may 
possibly be the type of Necker’s Asasiies, I think ; for, as I have 
shown already, it cannot be Gerbera, which is only an appended 
species, not the type. It seemsasif the type of Cassini’s Homo- 
gyne, that is Tussilago alpina, Linn., of which the involucre is 
more or less imbricated, may have stood with Necker for the type 
of Afasites. It is an European type which Necker must have 
known well enough, while with the then new and rare 7. 
nutans of the West Indies he may have been altogether unac- 
