90 WEEDS OF FARM LAND 



dry the sheaves most thoroughly as the bindweeds are apt to 

 cause heating in the stack. 



Vetches occasionally appear as farm weeds, though most of 

 them are typically hedge plants. They are climbers in which 

 the end leaflet of the compound leaf is modified into a tendril. 

 This is irritable and curls round any available support, enabling 

 the weak stemmed plant to drag itself up. 



Goosegrass (Galium aparine] does not climb, but scrambles 

 over and among the crops, clinging to them by the minute 

 hooked prickles with which every part of the plant is clothed. 

 The slender stems may reach a length of several feet, and 

 their clinging habit causes considerable interference with farm 

 operations. Goosegrass is only an annual, but under suitable 

 conditions it grows very rapidly, forming large numbers of 

 prickly fruits which are very easily picked up and carried 

 about by anything with which they come into contact 



(8) Weeds with Swollen Internodes. This habit, fortun- 

 ately, is unusual among farm weeds. In the knotty or onion 

 couch the portions of stem between the successive leaves are 

 swollen up into large knobs, several occurring in a string. 

 These are perennial, very tenacious of life, and resistant to 

 most attempts to eradicate them. Every " knot " will produce 

 a new plant, so that if the weed is broken by ploughing it is 

 encouraged to increase. If, again, the clusters of knots are 

 brought to the surface in cultivation and are allowed to dry, 

 they separate into the individual knots, and additional plants 

 result. It is therefore specially important that this weed should 

 be cultivated out with as little breakage as possible, and 

 should be promptly removed from the soil before it dies and 

 breaks up. 



(9) Bulbs. The weeds that belong to the Lily family are 

 characterised by bulbs, which are underground clusters of 

 swollen scale leaves springing from a small flattened stem. 

 Buds arise between these scale leaves and develop into new 

 bulbs, and seeds are also produced, so that such weeds as 

 meadow saffron (Colchicum autumnale] and Bath asparagus 

 (Ornithogalum pyrenaicum) have two certain methods of re- 

 production. Wild onion possesses a third method, as small 

 bulbils arise among the flowers, which fall to the earth and 

 develop into fresh plants. 



(10) Parasitic Weeds. These are few in number, but are 

 capable of working much havoc when they are present among 

 crops. Their habit is to attach themselves, by means of suckers, 



