I. 



INTRODUCTION TO THE PLANT-LIFE OF THE 

 OXFORD DISTRICT 



ONCE free from streets and houses, considered as mere evidence of the 

 gregarious habits of a modern population with the quite natural obsession 

 that the world was specially designed for the welfare of the human race, 

 it is only necessary to take an unbiased view of the condition of the 

 surrounding country, to be inevitably inclined to the conclusion that, even 

 in this part of the world, where half the year is spent in a struggle with the 

 cold and storms of winter, Plant-life is enormously preponderant, and the 

 vegetation of the countryside is the primary phase of life to be considered 

 in dealing with all biological problems of the locality. 



Trees or grass clothe the visible surface of the land, in close canopy or 

 as thick undergrowth ; animal life, beyond a few birds and the animals 

 maintained by man, 1 is conspicuously inconspicuous. Towns appear but as 

 ant-heaps spaced far apart in the general green mantle of vegetation ; and 

 however much man may interfere with and attempt to dominate or even to 

 replace the indigenous flora, his attempts are of doubtful permanence. 



In point of time modern towns have a history of little over one thousand 

 years ; 2 that of the flora, even of this country, may be measured possibly in 

 hundreds of thousands ; and a modern city, with its fortuitous collection of 

 human beings, may as readily dissolve again, and their rejectamenta be lost 

 and buried under returning vegetation. An enthusiastic entomologist has 

 claimed that the present age is pre-eminently that of insects ; a medical writer 

 might with equal acumen describe it as the age of bacteria. Omitting any 

 considerations as to the relative importance of extreme lines of biological 

 development, there can be no question that in all ages, as the base of the 

 pyramid of life on this world, the autotrophic plant is the dominant factor 

 for all time. That is to say, the living plant, on which we are still mainly 

 dependent for our supplies of food and energy, is dominant in aggregate 

 mass and volume of living material, as also in vitality and staying power, 

 however much we may try to ignore the fact, and endeavour to extirpate 

 the last persistent weed. 



The flora of the British Islands, as a whole, is but the much deterio- 

 rated version of a European flora of the North Temperate zone ; the latter 

 again consisting mainly of successive migrants or survivals from a more sub- 

 tropical environment, as vestiges of families, often represented by single 

 genera, or by the last enduring species pushed farthest north. Of the 

 British types of vegetation, that of the central plain of England is, again, 

 the most inferior, in variety of forms, as of biological constituents. The 

 local Oxford flora can show no heath-moors, alpine slopes, sand-dunes, 

 shingle beaches or estuarine swamps, which have so attracted ecologists in 

 other directions ; 3 it remains characteristically commonplace, sylvestral, 

 agrestal, paludal, with no special developments in any direction, and with 



1 For statistics cf. Orr (1916), Agriculture in Oxfordshire. Approximately I sheep for i\ acres, 

 a cow or bullock for 7 acres, a pig to 20 acres, and a horse used in field-work to 40 acres. 



With intensive cultivation a cow may be kept on an acre of pasture, representing the photo- 

 synthetic output of some 5 million plants. 



8 The Oxford Millenary celebrated 1912. 



s Carey and Oliver (1908), Tidal Lands. 



Tansley (1911), Types of British Vegetation. 



