322 GEOGRAPHICAL DISTRIBUTION OF THE EQUISETACE#. 
who kindly sent it to me, together with all the other Equisetacee in his 
possession. The attempt Vaucher made could scarcely be expected to 
be satisfactory, as in his time collectors paid but little attention to the 
Equisetacee. The numerous travellers who afterwards brought home 
these plants often gave names to such forms as appeared to them dis- 
tinct, but without troubling their heads much about whether they might 
not possibly be identical with already described ones. Moreover, as till 
1844, when Professor Alexander Braun published his excellent mono- 
graph of the North American Zguisetacee,* no definite principles 
had been laid down for circumscribing the species, one botanist attach- 
ing importance to this, the other to that character, the nomenclature of 
the species became very much entangled ; an ‘ Index Equisetorum Om- 
nium? which I have made contains one hundred and sixty-three names for 
the twenty-six known species, and it is no slight trouble to introduce 
somewhat like order into such a chaos, A 
For years I have endeavoured to. examine original specimens of all 
doubtful species, and I have very nearly succeeded. Recently I have 
described monographically all the exotic species in the Transactions of 
the Zoologico-Botanical Society of Vienna. There are only two plants, - 
E. scandens, Remy (Enum. Plant. Vascul. Cryptog. Chilensium, Dr. 
I. W. Sturm, Nürnberg, 1858, pp. 48, 49), and E. pyramidale, Goldm. 
(‘Nova Acta,’ 1848, xi, Suppl. i. p. 469), both from Chili, which I have 
not been able to examine; they are probably only forms. of already 
known species; the diagnosis of the former. seems to agree well with 
E. Bogotense. Altogether, I know twenty-six species which are. thus 
distributed over the globe. : otint- 
From the continent which might be expected to. yield the most 
Equiseta, viz. Australasia, not one species is known. America contains — 
the most. species, viz. twenty-one, amongst them ten peculiar to that 
continent. Next ranges Europe, with thirteen species, only three of 
which are peculiar to it. Asia possesses eleven. species, of which two 
are peculiar. Africa has only two species, both of which are common 
to Europe also, yas 
. On turning to the New World, we find thatthe North American and 
South American species are distinct, only one species (E. Schaffne 
Milde) having as yet been met with both in North and South Americas 
* Silliman’s American Journal of Science and Art, vol. xlvi. — 
+ Jahrgang 1862. spiel] 
