927 



" On the Potato-Disease," by Dr. P. B. Ayres. 



" On the Potato-Disease," by Mr. W. Taylor, F.L.S.— C. E. D. 



Observations on the Descriptions of some of the Hieracia by Mr. 

 Babington in his ' Manual of British Botany^^- By James 

 Bladon, Esq. 



Being much interested in the different species of Hieracium, my 

 first employment after receiving the Manual was to examine the dif- 

 ferent specimens I had with Mr. B.'s descriptions. In some of his 

 descriptions he uses the expression ^^ glandular hairy ^'' which, by 

 being put in italics, may be considered as indioating a poi-tion of the 

 specific difference. In some of the other descriptions he uses the 

 word " seta," which, in botanical nomenclature, is understood to 

 mean a stiff bristle not bearing a gland. If he means any difference 

 between the above two expressions he has not been happy in the use 

 of them, as he describes H. murorum "with white stellate pubescence 

 and many black setae." In the specimens from Dursley (by Mr. Ste- 

 phens), distributed by the Society, the involucral scales and pedun- 

 cles are with black glandular hairs, not black setce. In the specimens 

 I have examined in this neighbourhood (amounting to some hun- 

 dreds) tliey are much more densely glandular-hairy, and less pubes- 

 cent than the Dursley plant, and without any common bristles or 

 hairs (setae) being interspersed among the gland-bearing ones. With 

 regard to his separating murorum from maculatum and sylvaticum as 

 a species distinct from either, I believe him to be correct. I have 

 observed them several seasons growing on the same bank, within a 

 few inches of each other in some instances, yet out of numbers there 

 was not one but might be distinguished at the first glance : the flow- 

 ers of murorum, although generally a much smaller plant, are consi- 

 derably larger than any of maculatum. 



The absolute necessity of examining the species of Hieracium dur- 

 ing the whole period of their growth, is instanced by his description 

 of sylvaticum and maculatum, which he has united under vulgatum. 

 Fries. He has inserted them in the section " Radical leaves present 

 at the time of flowering." I yesterday examined a great number of 

 plants of maculatum in a growing state, and found not one without 



* Read before the Botanical Society of London, 6th August, 1847. 



