228 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



B. microphylla, Roxburgh, 1820. — China, Japan. 

 This species is one of the best characterised of the genus, 

 and has produced double-flowered garden varieties. 



ROSE CONSTRUCTION— NORMAL AND ABNORMAL. 



Dr. Masters exhibited diagrams showing the ordinary con- 

 formation of the Rose, together with others representing 

 exceptional peculiarities. The speaker laid stress upon the 

 anatomical structure of the leaves, as affording an interesting 

 subject of study from its variety, and also from its probable 

 relation to the greater or less liability of particular roses to be 

 injured by mildew. Alluding to the mode of development of 

 the embryo-flower, the speaker showed how close was the real 

 relationship of the Rose to the Potcntilla and numerous other 

 genera, which at first sight seem to have little affinity to it. 

 A drawing was shown of a specimen collected by Dr. Shearer 

 in which the flower of a Scotch rose, Bosa spinosissima, showed 

 (by accident) exactly the construction of a Potentilla, the "hip " 

 being undeveloped. The "quartering" of some roses, such as 

 Souvenir de la Malmaison, and the varied arrangements of the 

 petals in others, were traced back to variations in the embryo- 

 flower affecting the number, arrangement, and degree of branch- 

 ing of the stamens, of which most of them are in reality the 

 modified representatives. 



Dr. Masters also showed flowers of Bosa berberidifolia 

 (received from the Rev. H. Ewbank), and stated the results of his 

 investigations into the peculiar characteristics of this remarkable 

 plant. He pointed out that the stipules, though apparently 

 wanting, are, at least potentially, present, and that the single 

 leaf represents the terminal leaflet of an ordinary rose leaflet, 

 the lateral ones not being developed. The characters of the 

 flower, which superficially is more like that of a Helianthemuvi, 

 were pointed out and shown to be in no important particular 

 different from those of ordinary single roses; hence the speaker 

 was of opinion that the plant, in spite of its peculiarities, was a 

 true rose, and that there was no sufficient ground for placing 

 it in a separate genus. A paper shortly to be published in the 

 " Bulletin " of the Royal Society of Botany of Belgium contains 

 full details as to the structure of this rose. 



