202 PITTONIA, 



I 



The English name, Thistle, essentially generic, embraces 

 as used a great variety of plants belonging to several more 

 or less technically formulated genera of tlie botanists, in a 

 number of natural orders. First it takes in many more or 

 less heterogeneous cynaroid composites, then a number of 

 cichoriaceous plants, and more unfortunately, certain poppies. 

 What botanist of experience is not familiar with the name of 

 Thisile as applied by the unskilled to the species of Arge- 

 mone? The vernacular term as popularly employed will 

 embrace almost all herbaceous plants which arm themselves 

 against our approach by a sharply spinescent foliage. It is 

 an extreme case of primitive crudeness in the delimitation of 

 a genus ; of a mistaken generalizing upon a marked pecul- 

 iarity of foliage. And yet it must be allowed that this very 

 case of the Thisiles is one which has given to the " scientific " 

 genus-makers one of the most difficult of problems^a prob- 

 lem actually no nearer its successful solution, we think, than 

 it was two centuries ago as Tournefort left it. For granting 

 that by our botanical science we readily exclude from the 

 alliance of Thistles all such incongruities as Sonchus and 

 Argemone, when it comes to the cynaroids themselves, we 

 wish to have several genera— believe that we ought to have 

 them, think that in nature they do exist— and are obliged 

 to fall back upon the methods of remote antiquity and make 

 our appeal to vegetative characters, such as foliage, and the 

 presence or absence of spines, in order to avoid merging a 

 whole suborder of plants in one genus. Tournefort gave his 

 support to the eight genera following : Cardiius, Cinara, 

 Jacea, Cyanus, Centciurium, Cirsium, Lappa and Cniciis. 

 Lmneeus, by reducing Jacea, Cyanvs and Ccntauriim to 

 one (i. e. Centaurea), brought the number down to six ; but 

 a reaction came, as more species were brought to light, so 

 that the Linnaean Centaurea, as augmented by these many 

 new species, within less than a hundred years from the 

 time of Linnaeus, had been subdivided by various authors 

 into more than thirty genera.^ Now whether, with ToArnefort 



See Benth. & Hook. f. Gen. ii. 478 



