42o SCIENCE PROGRESS 



There is one particularly vicious weed which happily is not 

 of very general occurrence — the so-called " Garlic " (Allium 

 vineale). The writer's experience of this plant is confined to 

 one district in the neighbourhood of Woburn (Beds) where it 

 grows on very heavy clay land. It is a member of the Lily 

 family and like all other plants in the order possesses a swollen 

 underground shoot or bulb and is able to increase in the usual 

 way by forming additional small bulbs at the base. Besides this, 

 very numerous seeds are formed which are an efficient means 

 of spreading the plant widely. But in addition to these two 

 normal methods of reproduction, there is a third which is less 

 usual. The flower-head consists of an umbel with a number 

 of flowers springing from one point; at the base of the pedicels 

 small bulbils are formed which ripen and become detached and 

 on reaching the ground start growing, giving rise to new plants. 

 Added to this, the plant possesses strong inherent vitality, so 

 that it is most difficult to kill it and almost impossible to get 

 rid of it without adopting very special measures. 



It is noticeable that the plants which are the most widely 

 spread and the most plentiful are those which are best provided 

 with large quantities of seed and with special means of dis- 

 tribution. Such plants have another characteristic which is 

 less obvious at first sight, in that they are very adaptable 

 in nature and able to establish themselves and settle down 

 happily under various conditions of soil and climate. On 

 reading the account of some of the Canadian weeds 1 one is 

 struck by the number of weeds that are reported as " introduced 

 from Europe," over a score of such being described, including 

 some of our most common pests — Curled Dock, Spurrey, 

 Charlock, Creeping Thistle and Corn Cockle. All these plants 

 have established themselves so well that they are now as 

 troublesome in Canada as they are in England. Another 

 striking fact is that many of the common British weeds are 

 native in Canada and that these are as serious nuisances 

 there as here. The Wild Oat, Couch, Sheep's Sorrel, Fat Hen 

 (Cheno podium album), Bindweed, Dodder, Field Sow Thistle 

 and Bladder Campion are among the species which are common 

 in both countries. 



1 J. E. Hewitt, Weeds of Ontario, 191 1 ; G. H. Clark and J. Fletcher, Farm 

 Weeds of Canada, 1 909. 



