m 



560 



REroijT — 1884. 



I 



genera and not far from ninety species. All Europe lias only seventeen 

 genera and bart.'ly fifty species. We have ost of the actual European 

 species, excepting their rhododendrons and their heaths, — and even the 

 latter are represented by some scattered patches of calluna, of which it may 

 be still doubtful whctlicr they are chance introductions or sparse and scanty 

 survivals ; and besides wo have a wealth of peculiar genera and species. 

 Among them the most notable in an ornamental point of view are the 

 rhododendrons, azaleas, kalniias, andromedas, and clcthras ; in botanical 

 interest, the endemic Ivtonotropca', of wlu'ch there is only one species in 

 Europe, bnt seven genera in Nortli America, all but one absolutely 

 peculiar; and in edible as well as botanical interest, the unexampled de- 

 velopment and diversification of the genus vaccinium (along with the 

 allied American type, gaylussacisi) will attract attention. It is interesting 

 to note the rapid falling away of ericacca) westward in the valley of the 

 Mississippi as the forest thins out. 



o. The wealth of this flora in compositai is a most obvious feature; 

 one especially prominent at this season of the year, when the open 

 grounds are becoming golden with solidago, and the earlier of the 

 autumnal asters are beginning to blossom. The composita) form the 

 largest order of phasnogamous plants in all temperate floras of the northern 

 hen^ispherc, are well uj) to the average in Europe, but are nowhere so 

 numerous as in North America, where they form an eighth part of the 

 whole. But the contrast between the composita) of Europe and Athmtic 

 North America is striking. Europe runs to thistles, to inuloidca), to 

 anthemidea!, and to cichoriarca?. It has very few asters and only two 

 Bolidagos, no sunflowers and liardly anything of that tribe. Our Atlantic 

 flora surpasses all the world in asters and solidagos, as also in sunflowers 

 and their various allies, is rich in eupatoriacea', of which Europe lias 

 extremel}" few, and is well supplied with rernoniacefc and helonioidea) of 

 which she has none ; but is scanty in all the groups that predominate in 

 Europe. I may remark that if our larger and most troublesome genera, 

 such as solidago and aster, were treated in our systematic works even in 

 the way that Nyraan has treated hieracium in Europe, the species of 

 these two genera (now numbering 7S and 1"2 I respectively) would be at 

 least doubled. 



4. Perhaps the most interesting contrast between the flora of Europe 

 and that of the eastern border of North America is in the number of 

 generic and even ordinal typos here met with which are Avholiy absent 

 from Europe. Possibly we may distinguish these into two sets of difl'ering 

 history. One will rofiresent a tropical clement, more or less transformed, 

 which has probably acquired or been able to hold its position so far north 

 in virtue of high summer temperature. (In this whole survey the penin- 

 sula of Elorida is loft out of view, regarding its botany as essentially 

 Bahaman and Cuban, with a certain admixture of northern elements.) 

 To the first type I refer such trees and shrubs as asimina, sole represen- 

 tative of the anonacea^ out of the tropics, and reaching even to lat. 42°; 

 chrysobalanus, representing a tropical sub-order; pinckneyarepreseiitinj» 

 as far north as Georgia the cinchoneous tribe ; the baccharis of our coast 

 reaching even to New England ; cyrilla and cliftonia, the former actually 

 West Indian ; bumelia, representing the tropical order sapotacea) ; bignonia 

 and tecoma of the bignoniacea) ; forestiera in oleaceaj; persea of the 

 laurineoc ; and finally the cactacea?. Among the herbaceous plants of this 

 set, I will allude only to some of peculiar orders. Among them I 



