2iib 



KNOWLEDGE 



[November 2, 1896. 



they are now spread all across that vast continent, from 

 Atlantic to Pacifii-. At the Cape of Good Hope, in New 

 Zealand and Australia, the same plants have established 

 themselves. But besides these comparatively modern 

 emigrants, the Canadian flora, for example, includes amont,' 

 its aboriginal plants such familiar ones as the wood- 

 auemone, water-crowfoot, ladies'-smock, scurvy-grass, 

 wood-sorrel, purple avens, strawberry, agrimony, sundew, 

 willow-herb, valerian, harebell, wliortleberry, crowberry, 

 cranberry, sea-lavender, thrift, and scores of others, to say 

 nothing of closely allied species of other genera. Some of 

 these plants may be commoner there ; others here. Of 

 course the aspect of the vegetation of a locality depends 

 upon the predominating species, and varies, according to 

 physical conditions, in places contiguous to each other; the 

 change often being very abrupt. 



In a former paper I mentioned the recurrence of the 

 crowberry {I-'inpctrum) in tb.e southern hemisphere. As 

 already stated, many northern plants reach the southern 

 hemisphere, but they usually inhabit suitable intermediate 

 localities, Lncluding the mountains of the tropics. Isolated 

 localities of other northern plants in the south are occupied 

 by the bird's-eye primrose (Priwula farinosa) — or a species 

 so near it as to render the fact equally remarkable — at Cape 

 Horn and the Falkland Islands ; and by the lady's-mantle 

 [AkJicwilla ruhjorix) in the Australian Alps. A parallel is 

 offered by the existence of the long-leaved sundew {Prosera 

 lonfjifolia) on the mountains of the remote Sandwich 

 Islands. 



The first botanical explorers of the peaks of Fernando 

 Po, St. Thomas Island, and the Cameroous in western 

 tropical Africa, discovered ijuite a large colony of Euro- 

 pean (chiefly liritish) plants, associated with types more 

 peculiarly African. Thirty-eight out of the fifty-six genera 

 collected are common to Britain, and upwards of twenty 

 species. Among the latter are the sanicle (SanicuJa 

 riiropiva), the navelwort (Coti/Mon rmhilicus), the devil's- 

 bit scabious {Scnbiosa snccisti'), the common goose-grass or 

 cleavers [(JaliKm nparine), and such comparatively rare 

 little plants as SihlJiorpia cnropn'a and Liiiio^ilUi (Kjuatica. 



Now a few particulars concerning some of the trees of 

 the British Islands. We have one species of oak (of which 

 there are several more or less distinct varieties), one species 

 of beech, one of ash, one each of alder, elm, hornbeam, 

 holly, yew, fir, and so on. Of willows there are two large 

 arboreous kinds, besides several that are large shrubs or 

 small trees. The distribution of the British species of 

 these trees, as well as the distribution and development of 

 the genera to which they belong, outside of Britain, is 

 exceedingly interesting. The British oak ((,'uerciis Ii'nlmr), 

 for instance, is spread nearly all over Europe, almost from 

 the Arctic Circle to the Mediterranean, and it extends to 

 Asia Minor ; so that we have no right to regard it as 

 specially British. In this wide area it varies considerably, 

 and one of the most striking varieties is found in the 

 Pyrenees. It so closely resembles the Lombardy poplar 

 as to be easily mistaken for it at a short distance. There 

 are trees of it in Kew Gardens. 



But our oak is only one out of at least three hundred 

 species of ijtiercus spread over Europe, Asia, and North 

 America, extending southward in America almost to the 

 Equator, and in Eastern Asia through the Malay Archi- 

 pelago to New (iuinea, the only part in which the genus 

 reaches the southern hemisphere. '■ In Africa oaks occur 

 only in the countries bordering the Mediterranean. The 



* In the Kew Herbarium there is a lealloss branch, bearing male 

 flowers, wliicli are exactly those of an oak. The spccimeu is from 

 the Pilcomayo River, between Paraguay and Argentina. 



variety of foliage and fruit exhibited by this long array 

 of species is surprising, and they are not less beautiful 

 than varied. Imagine an oik with glossy, shining leaves 

 eighteen inches in length, and elegant acorns three to four 

 inches across ! 



The distribution of beech trees (Fniinx) is very dilTorent, 

 the greatest concentration of species being in the southern 

 hemisphere, where, in the extreme south of America, in 

 New Zealand, in Tasmania, and in the mountains of 

 South-Eastern Australia, they form large forests. In 

 New Zealand, where there is the greatest development, 

 they are universally called birch trees. 



Willows {Sali.f) are specially numerous in north 

 temperate and cold regions, and about twenty small 

 shrubby species are found within the Arctic Circle, forming 

 a good part of the woody vegetation. But willows are not 

 restricted to the regions named ; they are also found in 

 hot and dry regions, and, curiously enough, they inhabit 

 just those countries in which there are no oaks. In 

 America there is one species which ranges from North 

 Mexico, through Central America and the West Indies, to 

 Chili and Argentina. In Africa there are several species, 

 one being common on the banks of the Garlep or Orauge 

 Eiver and elsewhere in South Africa. In Asia, willows arc 

 not found south of the Malay Peninsula, where, however, 

 one species descends the rivers to the tidal forests of tropical 

 Pegu and Tenasserim. The genus is altogether unrepresented 

 in the Malay Archipelago, Polynesia, and New Zealand. 



Our holly (//<.(), again, is one species out of about 

 one hundred and fifty belonging to the genus. It has a 

 wide range in Europe, from Southern Scandinavia to the 

 Mediterranean, and eastward to the Caucasus. The genus 

 is widely spread in warm and temperate countries, though 

 rare in Africa and Australia, and not reaching New 

 Zealand. In China and Japan hollies are numerous, 

 there being about fifteen species in the latter country. 



The mention of Japan suggests a few comparisocs 

 between the floras of the British and Japanese Islands. 

 Similarly situated with regard to the nearest continent, 

 though in a considerably lower latitude, Japan enjoys 

 about the same average winter temperature as England, 

 with a higher summer temperature. The approximate 

 number of species of flowering plants and ferns in- 

 three thousand, or double that of 

 1 have mentioned that there is a 

 stretching from the Atlantic across 

 to the Pacific, in which a large 

 percentage of the plants are specifically the same. China 

 Proper and Japan lie just without this zone, though it is 

 true that a considerable number of species are common 

 to those countries and Britain ; but they are lost among 

 the very numerous species peculiar to the region. Upwards 

 of forty per cent, of the species are peculiar to Japan, 

 besides a number of genera. Instead of one species of each 

 of the various kinds of forest trees, it has twenty-two 

 species of oak, as many of maple, fifteen hollies, fifteen 

 pines and firs, six birches, four hornbeams, four alders, and 

 three elms, to say nothing of a host of others belonging 

 to natural orders not represented in the British Islands. 

 There is also an abundance of shrubs and trees, both 

 evergreen and deciduous, which bear showy flowers ; and 

 the herbaceous plants, taken as a whole, are more 

 brilliantly coloured than our own. Fortunately our climate, 

 with all its faults, is favourable to the development of 

 many of the ornamental plants of the Far East. I need 

 only mention such genera as PiivniVi, Aster, Chiymntlwmwn, 

 Clematis, Berberls, Aiicuha, Wistaria, Vamdlia, Maijiiolia, 

 and the numerous evergreen members of the cypress and 

 fir family. 



habiting Japan is 

 the British Islands, 

 zone of vegetation 

 Europe and Asia 



