784 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Herbaceous Plants, New. By Kache (Gartenflora, vol. lxii. pt. iv. 



pp. 75-78 ; 2 figs.). — Artemisia lacli flora, a native of China, forms a 

 bush 6 feet in height, covered with dark-green foliage. From August 

 to October it is covered with panicles of flowers which are greenish- 

 yellow when they open, but change to milk-white. It prefers a rather 

 heavy moist soil in half shade. 



Thalictrum dipterocarpum comes from China. It resembles T. 

 aquilegi folium, but is larger and is more beautiful in the colour of its 

 foliage. It is covered with flowers from August until it is cut down 

 by frost. The blooms are pink to lilac-blue in colour. The Thalictrum 

 enjoys exposure to full sun and good drainage. — 5. E. W. 



Hollow Trees. By W. J. Bean (Bull. Roy. Bot. Gard., Kew, 

 No. 7, 1912, pp. 338-339 ; 2 plates). — " There is no doubt that hollow 

 places in the trunks and limbs of trees formed by decay are better 

 filled up," and the article describes the way in which that object 

 can be best accomplished. 



The cavity should first be cleared of all decaying material, and 

 the surface of the wood thus exposed should be washed with a strong 

 solution of carbolic acid. After allowing a day or two to dry, a good 

 thick coating of ordinary tar should be laid on. The cavity should 

 then be filled, using, if it be a small one, Portland cement, or if a large 

 one, a layer of bricks, which should afterwards be surfaced with cement. 

 A surface over which the new bark can grow is thus provided, and if 

 the tree is in a vigorous state, as many hollow trees are, the bark 

 will in time close over the " stopping." 



The majority of decayed hollows have their origin in snags left 

 by branches which have been broken off, and which have rotted 

 back into the trunk. Branches removed by design, or broken off by 

 wind or accident, should always be sawn off close to the trunk, and 

 the sawn surface should be coated over with ordinary coal tar. — A. S. 



Hop Mildew.^ By F. M. Blodgett (U.S.A. Exp. Stn., Cornell, 

 Bull. 328 ; March 1913 ; figs.). — After an account of the mildew 

 and notes on the relation between the weather and infection, methods 

 of control are described. From forty to seventy-five pounds of very 

 finely ground sulphur applied on an acre of hops gave the best results. 

 The sulphur was found to act as a good preventive. Flowers of 

 sulphur give better results than the usual coarsely-ground sulphur 

 flour. — F. J. C. 



Hybrids, Comparison of Structure with Parent Plants. By F. R. 



Brown (U.S.A. Exp. Sin., Mississippi, Bull. 3, 52 pp. j 38 figs.) — 

 The title sufficiently indicates the scope of this paper. An historical 

 review is given, and a bibliography. The plants especially studied 

 are Nicoliana, and Kohlrabi and Radish. 



The majority of histological characters are found to be intermediate. 



E. A. Bd. 



