Jan. 8, 1885] 



MA TURE 



2 33 



speech and that of tlie " Americans." The differences between 

 the Beei hes and Larches of the two countries are a little more 

 accentuated ; and still more those of the Hornbeams, Elms, 

 and the nearest resembling Oaks. And so of several other 

 trees. Only as you proceed westward and southward will the 

 overpower the similarities, which still are met with. 

 In the fields and along open roadsides the likeness seems to 

 be greater. But much of this likeness is the unconscious work 

 of man, rather than of Nature, the reason of which is not far to 

 seek. This was a region of forest, upon which the aborigines, 

 hey here and there opened patches of land for cultiva- 

 uiade no permanent encroachment. Not very much of 

 the herbaceous or other low undergrowth of this forest could 

 bear exposure to the fervid summer's sun ; and the change was 

 too abrupt lor adaptive modification. The plains and prairies of 

 the great Mississippi Valley were then too remote for their 

 vegetation to compete for the vacancy which was made here 

 when forest was changed to grain-fields and then to meadow and 

 pasture. And so the vacancy came to be filled in a notable 

 measure by agrestial plants from Europe, the seeds of which 

 came in seed-grain, in the coats and fleece and in the imported 

 fodder of cattle and sheep, and in the various but not always 

 apparent ways in which agricultural and commercial people 

 unwittingly convey the plants and animals of one country to 

 another. So, while an agricultural people' displaced the 

 aborigines which the forest sheltered and nourished, the herbs, 

 purposely or accidentally brought with them, took possession of 

 the clearings, and prevailed more or less over the native and 

 rightful heirs to the soil, — not enough to supplant them, indeed, 

 but enough to impart a certain adventitious Old World aspect to 

 the fields and other open grounds, as well as to the precincts of 

 habitations. In spring-time you would have seen the fields of 

 this district yellow with European Buttercups and Dandelions, 

 then whitened with the Ox-eye Daisy, and at midsummer 

 brightened by the ca?rulean blue of Chicory. I can hardly 

 name any native herbs which in Ike fields mid a! t/u- . 

 vie with these intruders in floral show. The commen Barberry 

 of the Old World is an early denizen of New England. The 

 tall Mullein, of a wholly alien race, shoots up in every pasture 

 and new clearing, accompanied by the common Thistle, while 

 another imported Thistle, called in the States "the Canada 

 Thistle," has become a veritable nuisance, at which much 

 legislation has been levelled in vain. 



According to tradition the wayside Plantain was called by the 

 American Indian "White-Man's foot," from its springing up 

 wherever that foot had been planted. But there is some reason 

 for suspecting that the Indian's ancestors brought it to this 

 continent. Moreover there is another reason for surmising that 

 this long-accepted tradition is factitious. For there was already 

 in the country a native Plantain, so like Plautago major that the 

 botanists have only of late distinguished it. (I acknowledge my 

 share in the oversight.) Possibly, although the botanists were 

 at fault, the aborigines may have known the difference. The 

 cows are said to know it. For a brother botanist of long 

 experience tells me that, where the two grow together, cows 

 freely feed upon the undoubtedly native species, and leave the 

 naturalised one untouched. 



It has been maintained that the ruderal and agrestial Old 

 World plants and weeds of cultivation displace the indigenous 

 ones of newdy-settled countries in virtue of a strength which they 

 have developed through survival in the struggle of ages, under 

 the severe competition incident to their former migrations. And 

 it does seem that most of the pertinacious weeds of the Old 

 Wi irld which have been given to us may not be indigenous even to 

 Europe, at least to Western Europe, but belong to campestrine 

 or unwooded regions farther east ; and that, following the move- 

 ments of pastoral and agricultural people, they may have played 

 somewhat the same part in the once forest-clad Western Europe 

 that they have been playing here. But it is unnecessary to 

 build much upon the possibly fallacious idea of increased 

 strength gained by competition. Opportunity may count for 

 more than exceptional vigour ; and the cases in which foreign 

 plants have shown such superiority are mainly those in which a 

 forest-destroying people have brought upon newly-bared soil the 

 seeds of an open-ground vegetation. 



The one marked exception that I know of, the case of recent 

 and abundant influx of this class of Old World plants into a 

 naturally treeless region, supports the same conclusion. Our 

 associate, Mr. John Ball, has recently called attention to it. 

 The pampas of South-Eastem South America beyond the Rio 



Colorado, lying between the same parallels of latitude in the 

 south .In Montreal and Philadelphia in the north, and with 

 climate and probably soils fit to sustain a varied vegetation, and 

 even a fair proportion of forest, are not only treeless, but exces- 

 sively poor in their herbaceous flora. The district has had no 

 trees since its comparatively recent elevation from the sea. As 

 Mr. Darwin long ago intimated : "Trees are absent not because 

 they cannot grow and thrive, but because the only country from 

 which they could have been derived — tropical and sub-tropical 

 South America — could not supply species to suit the soil and 

 climate.'' And as to the herbaceous and frutescent species, to 

 continue the extract from Mr. Ball's instructive paper recently 

 published in the Linnean Society's_/i>«?-«3/, "in a district raised 

 from the sea during the latest geological period, and bounded on 

 the west by a great mountain-range mainly clothed with an 

 alpine flora requiring the protection of snow in winter, and on 

 the north by a warm temperate region whose flora is mainly of 

 modified sub-tropical origin — the only plants that could occupy 

 the newly-formed region were the comparatively few which, 

 though developed under very different conditions, were sufficiently 

 tolerant of change to adapt themselves to the new environment. 

 The flora is poor, not because the land cannot support a richer 

 one, but because the only regions from which a large popula- 

 tion could be derived are inhabited by races unfit for emi- 

 gration." 



Singularly enough, this deficiency of herbaceous plants is 

 being supplied from Europe, and the in-comers are spreading 

 with great rapidity ; for lack of other forest material even apple- 

 trees are running wild and forming extensive groves. Men and 

 cattle are, as usual, the agents of dissemination. But colonising 

 plants are filling, in this instance, a vacancy which was left by 

 Nature, while ours was made by man. We may agree with Mr. 

 Ball in the opinion that the rapidity with which the intrusive 

 plants have spread in this part of South America "is to be 

 accounted for, less by any special fitness of the immigrant 

 species, than by the fact that the ground is to a great extent 

 unoccupied." 



The principle applies here also ; and in general, that it is 

 opportunity rather than specially acquired vigour that has given 

 Old World weeds an advantage may be inferred from the beha- 

 viour of our weeds indigenous to the country, the plants of the 

 unwooded districts — prairies or savannas west and south — which, 

 now that the way is open, are coming in one by one into these 

 eastern parts, extending their area continually, and holding their 

 ground quite as pertinaciously as the immigrant denizen-. Al- 

 most every year gives new examples of the immigration of cam- 

 pestrine western plants into the Eastern States. They are well 

 up to the spirit of the age : they travel by railway. The seeds 

 are transported, some in the coats of cattle and sheep on the 

 way to market, others in the food which supports them on the 

 journey, and many in a way which you might not suspect, until 

 you consider that these great roads run east and west, that the 

 prevalent winds are from the west, that a freight-train left un- 

 guarded was not long ago blown on for more than one hundred 

 miles before it cauld be stopped, not altogether on down grades, 

 and that the bared and mostly unkempt borders of these railway- 

 form capital seed-beds and nursery-grounds for such plants. 



Returning now from this side-issue, let me advert to another 

 and, I judge, a very pleasant experience which the botanist and 

 the cultivator may have on first visiting the American shores. 

 At almost every step he comes upon old acquaintances, upon 

 shrubs and trees and flowering herbs, mostly peculiar to this 

 country, but with which he is familiar in the grounds and 

 dens of his home. Great Britain is especially hospital le to 

 American trees and shrubs. There those both of the 1 astern 

 and western sides of our continent flourish side by side. Here 

 they almost wholly refuse such association. But the most 

 familiar and longest-established representatives of our flora 

 (certain western annuals excepted) were drawn from the Atlantic- 

 coast. Among them are the Virginia Creeper or Ampelop is. 

 almost as commonly grown in Europe as here, and which, I 

 think, displays its autumnal crimson as brightly there as along 

 the borders of its native woods where you will everywhere 

 meet with it ; the Red and Sugar Maples, which give the notable 

 autumnal glow to our_ northern woods, but rarely make much 

 show in Europe, perhaps for lack of sharp contrast between 

 summer and autumn ; the ornamental Ericaceous shrubs, Kal- 

 mias, Azaleas, Rhododendrons, and the like, specially called 

 American plants in England, although all the Rhododendrons 

 of the finer sort are half Asiatic, the hardy American species 



