86 Plant-life of the Oxford District 



and go, leaving little trace behind. Strictly speaking, there is not the 

 slightest reason why there should ever be a 'weed' at all in any well- 

 conducted allotment-area ; the facilities for checking their growth in manual 

 cultivation being sufficiently ample. 



The amount of land locally under such allotment cultivation is already 

 considerable. The ground had been previously pasture-fields, cut for hay 

 (Donnington), grazed (Port Meadow), used for cricket grounds (CowleyRoad), 

 and largely flood-meadows of the alluvium (Osney, Botley), with attempted 

 raising of the level by means of town-refuse (Port Meadow). The oldest 

 tracts and those nearest the city are on the alluvium (Port Meadow Allot- 

 ments). The soil in these cases is Oxford Clay (Holywell), or with super- 

 imposed alluvium, or in the case of Port Meadow, alluvium over terrace- 

 gravel ; at Headington there are extensive allotments on Corallian soils. 

 In all cases the antecedent flora had been that of pasture-land ; and with 

 the clearing of the turf, grasses and the weeds of pasture remain to some 

 extent, in the borders, hedges, and foot-ways, while other weeds of cultiva- 

 tion and of human association are introduced. Since such intrusives may 

 become a nuisance, they are regarded as ' weeds ' to be kept down by the 

 cultivator in his own interest and also in that of his neighbours. 1 



Allotment-weeds are chiefly of annual duration (including ephemerals), 

 commonly growing up with the crop ; their maintenance depending largely 

 on the fact that their periodicity runs parallel with that of the cultivated 

 plant ; while weeding may be difficult in later stages of growth. With the 

 general run of summer annuals are included some particularly deep-rooted 

 perennials, surviving in virtue of a deep root or rhizome-system in the lower 

 layers of the subsoil, with great vitality and powe^ of vegetative propaga- 

 tion, the cutting of rhizome or root into pieces by the spade only serving 

 to increase the number of individuals. It is a matter of interest to consider 

 the origin and possibilities of such a flora, its special means of perennation 

 and capacity for rapid multiplication, as much from the standpoint of the 

 remarkable vitality of such plant-forms, as from the converse standpoint of 

 the readiest means of effectively extirpating them. The special equipment 

 which enables such plants to hold their own comprises one or more of the 

 following factors : 



(i) Special mechanism of dispersal, preferably by wind. 



(a) Special mechanism of perennation. 



(3) Rapid rate of germination in open ground ; i.e. faster than the crop. 



(4) Early flowering and seeding, also earlier than the crop, with prefer- 



ably the monocarpic habit, as using up all available synthesized 

 material in the production of seeds, with extreme wastage- 

 coefficient. 



While weeds of arable land may be graded according to their response 

 to ploughing in winter and spring, with two sets of climatic conditions, 

 allotment- weeds may be graded roughly in three such sets, according as : 



(1) They begin as seedlings germinating in spring (April, May) as the 



first ' main crop '. 



(2) Later crops of seedlings germinating in favourable rainy weather in 



the early summer (June), and flourishing at midsummer. 



1 Ashby (1917), loc. cit., p. 20, for general by-law. One derelict patch will infect a wide area, 

 and involve considerable unnecessary labour for better workers. Uncultivated allotments become 

 a forest of weeds in early June, already seeding and hiding the soil, and ground is commonly 

 neglected in late summer. Weeds are soon reduced if the waste-heaps, hedges, and foot-ways, 

 are properly looked after; this being considered beyond the province of the individual holder. 

 Some of the more obvious and objectionable forms should be definitely proscribed, and their growth 

 made a punishable offence. At present, plants only become illegal when they act as hosts to some 

 fungus ' disease ' of the crop ; but attention to a few common weeds for a few seasons might wholly 

 eliminate them from the district. The method has been tried in other countries. 





