258 



T^E CANADIAN HORTICULTURIST 



little black and red burnet moths, 

 wliicli prefer the long bell-shaped blos- 

 soms even to that favorite flower with 

 them, the bird's-foot trefoil. Almost 

 every head in the field is covered by 

 half a dozen moths at once, all drink- 

 ing nectar from the i^ecesses of the deep 

 long tube, and all unconsciously carry- 

 ing pollen from stem to stem on their 

 uncoiled proboscis. But even after the 

 thistle tribe had separated from its 

 sister composites of the daisy and dan- 

 delion groups, it was far fi-om having 

 reached the fully developed thistly type. 

 The lower members of the tribe have 

 no prickles, and some of them are very 

 simple, unarmed weeds indeed. The 

 conmion sagwort, which abounds in 

 copses and hangers in the south of 

 England, represents the hrst rough 

 draft of a thistle in this nascent con- 

 dition. To look at, it is very thistle- 

 like indeed, especially in its })urple 

 flovver-heads, closely surrounded by a 

 set of tight but not prickly bracts. 

 Living as it does in bushy })laces, how- 

 ever, where cnttle seldom penetrate, it 

 has not felt the need of protective de- 

 fences, and so it has not been ousted 

 from its own special haunts by the later 

 and more higlily developed true thistles, 

 which are by origin weeds of the open 

 grass-clad lowlands, evolved undei stress 

 of damage from herbivorous animals. 

 But where cows and horses abound, or, 

 still earlier, where deer and antelopes 

 are common, tiie defenceless sagwort 

 would have little chance, aiul under 

 such circumstances only the harder and 

 stringier plants, or those which show 

 some tendency to produce protective 

 spines and bristles could hope for suc- 

 cess in the struggle for existence. Thus 

 there has arisen a natural tendency in 

 the level plains to favor all weeds so 

 protected ; and, as a matter of fact, 

 the vast majority of open lowland 

 weeds at the pi-esent day do actually 

 possess some protective device of stings. 



harsh hairs, prickles, or spines, or else 

 are very stringy or very nauseous to the 

 taste. Our object as cultivators is 

 generally to keep down these natively 

 well-eiidowed races, in favor of the 

 softer grasses and clovers, which we are 

 obliged artificially to fence in and pro- 

 tect with all possible precautions. But 

 even so, in spite of all our endeavoi's to 

 expel nature with our civilized pitch- 

 fork, " tamen usque recurrit." The 

 thistle that is overrunning the home- 

 close ranks, indeed, is among the 

 best adapted and most successful of its 

 kind, which is only the converse way of 

 saying that it is a most troublesome 

 and ineradicable weed. Creeping thistle, 

 we call it, from its peculiar habits ; for, 

 besides its open mode of propagation 

 by its floating seeds, it has a sneaking 

 trick of spreading underground by its 

 buried root-stock, which sends up fresh 

 stems every year from the joints or 

 nodes. It is the commonest of all its 

 i-ace, not in England only, but through- 

 out the globe ; for its winged fiuits 

 have been carried to every quarter of 

 the world with seed coi'ii and clovers. 

 Cut it down, and a new head springs 

 from below the wound ; hack it close 

 to the ground, and the root- stock [)ushes 

 out a fresh yoinig shoot from an unsus- 

 pected corner ; harrow it up bodily, 

 and the seed blows over at harvest 

 time fi'om all the surrounding fields, 

 just at the right moment for theautumn 

 ploughing. For hardiness of constitu- 

 tion it has no equal, and this is ])artly 

 due no doubt to the fact that universal 

 cross-fertilization has become absolutely 

 certain by the separatioii of the sexes 

 on different phmts. This globular head 

 that I have just swished off has none 

 but stamen bearing florets ; this other 

 more conical cluster, that I am trying 

 to cut with the aid of my knife and 

 handkerchief, contains nothing, on the 

 contrary, but pistils and seeds. Such 

 careful separation of the two elements 



