1642] 



NOTE ON THE DISTRIBUTION OF XANTHIUM 

 SPINOSUM: LINN^US. 



BY GEORGE JENNINGS HINDE, P.G.S. 



(Read before the Canadian Institute, November 3rd, 1877.) 



This plant, though generally affecting a more southerly climate, 

 appears to have established itself in the sheltered valley of Dundas, ' 

 at the western extremity of Lake Ontario ; the only spot in Western 

 Canada in which it is known to occur. Though it has been noticed 

 here for at least seven or eight years past, it does not appear to have 

 extended its area of growth to any adjoining locality ; and if the 

 facility with which the seeds attach themselves to passing objects 

 and are thus transported, be taken into account, the restriction of its 

 growth to this one place seems owing to the unsuitability of the 

 climate in places less sheltered than the Dundas valley. 



In common with a host of other plants now thoroughly naturalized 

 on this continent, this species has been introduced from Europe, but 

 whether it has been brought to this northern continent directly, or by 

 the circuitous way of South America, is open to question. Linnaeus 

 gives its habitat as France and Portugal ; it has come under my own 

 notice in Italy ; and in. Loudon's Encyclopaedia of Botany, it is noted 

 as growing in the South of Europe generally. In Buenos Ayres, and 

 some other Provinces of the Argentine Bepublic in South America, 

 the soil and climate are very favourable to its growth, and by means 

 of the numerous cattle and sheep which pasture on the fenceless 

 pampas, the seeds are readily distributed. The great extension of 

 sheep-farming in these countries within the last few years has been 

 the means of very widely spreading this troublesome weed, for not 

 only do the sheep transport the burrs in the wool, but they feed 

 down closely the native flora, and thus afford a better opportunity 

 for this intruder to gain a root-hold. Thus districts in the pampas 

 previously free from this weed, become, very soon after the introduc- 

 tion of sheep, infested with it. There is every probability that the 



