844 



in general they are less hoary, excepting, as we have just seen, in the 

 suckers or very young seedlings, they are even sometimes smooth and 

 glabrous, as above, or hoary in patches, as if with mildew. Such a 

 glabrous form, of which I find a moderately large but perfectly bar- 

 ren tree in a heathy pasture near Pagham farm, in this island, I sup- 

 pose may be the P. canescens, var. /3. intermedia of Merat (Nouv. Fl. 

 des Env. de Paris, p. 400), and which he thought, not improbably, 

 might be a hybrid of this species with P. tremula,* but like myself, 

 the fructification was unknown to him. Lejeune (Fl. de Spa, p. 260) 

 thinks it more allied to P. tremula than to P. canescens, and although 

 believing it to be a variety of the aspen, makes it a species (P. inter- 

 media, Mer.), in order, as he says, to draw attention to its characters; 

 a bad principle to go upon in botany as in ethics. It is also, accord- 

 ing to Gaudin (Fl. Helv. vi. p. 289), the P. alba, y. denudata of 

 Spenner, Fl. Frib. ii. p. 274, and I think it probable to be likewise 

 the P. hybrida of M. Bieberstein, Fl. Tau. Caucas. ii. p. 422, as 

 drawn at least by Reichenbach (Icones Fl. Germ. tab. 615), for the 

 description of Bieberstein does not quite agree with the figure. For 

 my own part, not having seen fructification, I know not whether to 

 look on the Pagham tree as a hybrid or a subglabrous variety or ra- 

 ther state of P. canescens, but am more disposed to the latter opinion. 

 The next point to be considered is the alleged difference in the 

 form and number of the stigmas in our two poplars, and here I am 

 unfortunately not in a condition to offer any opinion from personal 

 research, having hitherto failed in all my efforts to obtain pistillate 

 catkins of P. alba and P. canescens. These trees do not flower here 

 till they have reached a very considerable height, when the catkins 

 are for the most part quite out of reach, and produced chiefly on the 

 highest boughs. The few catkins of P. alba I have been able to pro- 

 cure have been staminate ones, and I suspect the pistillate plants are 

 much rarer than those of the other sex, as I think is the case with P. 

 tremula as well. I can therefore at present only collect the observa- 

 tions of others, and consult plates of the species, from which, and 

 from what I have seen of the same organs in P. tremula, I am forced 

 to infer that no reliance can be placed on the number or even shape 



* The great affinity in structure between Salix and Populus renders it highly pro- 

 bable that hybrids are occasionally produced betwixt species belonging to the latter 

 genus, but the stigmas in Populus are less exposed and the pollen less attractive to 

 bees than in the willows, mules would therefore naturally be less common amongst the 

 poplars than the willows. 



