5: ga mt have. tose ‘ institute, w oe 
Notice of a Flora of North America. 981 
been founded on native specimens by European botanists, are 
unknown to our authors; and no less than twenty-two species, 
professedly described originally from garden specimens, (some of 
them of doubtful origin,) have not been identified with native 
cane On this subject, Dis. Torrey and Gray remark: 
. “Tt is well known that many of the enumerated species, both of 
earlier and later authors, have been described from plants long cultiva- 
ted in European gardens, where they have doubtless undergone great 
alterations in appearance ; to’ say nothing of the strong probability of 
occasional hybridization. A large and indeed increasing num 
these are only known as garden plants; and it is probable that many 
will never be identified with their original types ; even supposing them 
to have been derived in all cases from this country, which is by no 
means certain: As we have ‘chiefly directed our attention to the indi- 
genous plants, and have drawn our. descriptions from these alone, we 
have thought it.advisable to bring together, at the close of our account 
of the proper. Asters known tous, those species of garden origin 
which w re specimens. _ 
identified with nati A fuller compar- 
eee. their number. 
ference of soil, exposure, ‘season, ape be. rez 
at numerous reductions of species, ‘which others may think v 
ranted. We have only to say, that we have ‘seldom | ventured onal 
such reductions, ‘except on the authority of a full suite, of specimens 
afuller series, and thus’ loses its value as a means of distinction ; but 
the claims of a genuine species are generally confirmed by a 
numberof specimens. It. sities however, be admitted, that in this as 
in all large and natural genera, several species which we cannot but 
consider as distinct, ( sei Pasi instance as A. cordifolius and A sagitti- 
folius,) do frequently present very puzzling intermediate forms; and 
that an apparent transition is not always Teal. Yet it is better, per- 
haps, to hazard the occasional reduction of even true species to varie- 
ties, than to multiply species which we. are confessedly unable to de- — . 
a We may remark i in conclusion, that we are the more inclined to 
act pon our own convictions, on account of the very Frequent and 
wide disagreement avert of the highest authorities upon! wad genus.” 
eae mpm es pHa a inten SiN i aides dienianess 
; | vations a yi d wi 
has xut, 9 eesti a. 
