34 OBSERVATIONS ON HOLL’S LIST. 
Linnzeus only from Boccone or Barrelier, must have existed 
in Linneus’ Herbarium in Smith’s possession. Now, from 
Smith’s plant mine differs in having whorls of 8 rigid, not 6 or 
even fewer “pliant,” leaves; and the petals obtuse and mucro- 
nate, not “taper pointed.” These are some of the most strik- 
ing points of differences, but others exist: and though with 
no better means of judging than from the description, I con- 
sider myself fully warranted in keeping my plant distinct from 
this, and, therefore probably from the genuine G. aristatum, 
Linn. If, however, it prove that no authentic specimen 
really exist in the Linnzean Herbarium of his plant, Smith's 
will be entitled to no more authority than the conjectures of 
others are, and G. aristatum, Linn., must ever continue involv- 
ed in doubt andobscurity. On every ground, therefore, Ifindno 
reasonable pretence to admit the name as a designation of- 
the Madera plant, which, indeed, always appeared to me more 
nearly allied to G. cinereum, All., than to any thing described 
under the name of G. aristatum, Linn.: and I am even now 
not without doubts whether it may really be deemed sufficiently 
distinct from that species. In the Banksian Herbarium, it is 
referred to G. Mollugo, Linn.; from which, however, it is 
quite distinct: this, by the way, is a curious coincidence in 
the chain of conjectures about G. aristatum, Linn. The - 
Madera plant is referred by Höll to G. aristatum, L.; and = 
in the Banksian Herbarium to G. Mollugo, L.; and again L. 
aristatum, L., by De Candolle to G. Mollugo: the Banksian 
Herbarium thus directly affirming the same identification, 
which only follows, by necessary inference, from the inde- 
pendent conjectures of De Candolle and Mr. Holl The 
erroneous result, though suported by the Banksian Herba- 
rium, proves an error to lie with one or the other of these _ 
botanists. 
** Carlowitzia salicifolia, Moench,” is entirely a rock plant, 
not very unfrequent in the ravines of the interior. 
“ Ageratum conyzoides, Linn.,” is common every where 
below 1000 feet, by water-courses, or in waste moist ground 
by road-sides. 
