336 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Oak, Polyporus dryadeus, A Root Parasite of. By W. H. 



Long {Jour. Agr. Research, i. pp. 239-250, Dec. 1913 ; plates). — ^This 

 fungus (which is not the P. dryadeus of Hartig, which is, according to 

 the author, P. dryopMlus) is a root parasite of the oak, producing a 

 white sap rot and a heart rot in the roots. In all cases examined 

 there was no extension of the rot into the trunk, only the underground 

 parts being affected. Trees growing under unfavourable conditions 

 appeared most susceptible to the disease, which does not appear to 

 spread readily from tree to tree. The disease is widely spread in 

 America and in Europe, and attacks several species of oak. — F. J. C. 



Oak, Three Undescribed Heart-Rots of Hardwood Trees. By 



W. H. Long {Jour. Agr. Research, i. pp. 109-128, Nov. 1913 ; plates) . 

 — A review of various forms of heart-rot is followed by a discussion 

 of a "piped " or " pocketed " rot in various species of Quercus and 

 Castanea brought about by Polyporus Pilotae, a " string and ray " 

 rot of oaks due to P. Berkleyi, and a straw-coloured rot caused by 

 P. Jrondosus. — F. J. C. 



Olearia semidentata {Bot. Mag. tab. 8550). — Chatham Islands. 

 Nat. Ord. Compositae, Trihe, Asteroideae. Shrub, 4 feet high. Leaves 

 many, i J-2J inches long. Heads, terminal, 2-2^ inches across. Ray- 

 florets 50 and disk florets purple. — G. H. 



Orange, Black Rot of. By Edw. O. Amundsen {U.S.A. St. 

 Com. Hort., Cal., Bull., May 1913, vol. ii. No. 5 ; 8 figs.). — Compared 

 with other diseases of the citrus fruits and trees, this is not of much 

 economic importance, but there is always the possibility that the 

 percentage of infection may run high under favourable conditions for 

 the dissemination and propagation of the disease-producing spores. 

 Alternaria citri Pierce and Ellis is the fungus which causes the black 

 rot. It will propagate on many kinds of vegetable matter, and the 

 conidia are disseminated to the blossoms or fruit in the spring or early 

 summer. The fungus is primarily a saprophyte, but becomes a parasite 

 if introduced into the fruit. 



As it is difficult to apply a fungicide, infection must be prevented by 

 destroying all decaying vegetable matter in or near the orange groves. 



Other subjects dealt with in this bulletin include " Sweet Potato 

 Weevil," " Date Palm Scales and their Control," and " Fungus Gardens 

 Cultivated by Ants." — V. G. J. 



Paeonies {U.S.A. Dep. Agr., Bull. 527,1913, pp. 5-7; i fig.)-— 

 The American Pseony Society recommends for cut flowers the following : 



White. — Festiva Maxima, Couronne d'Or, Duchesse de Nemours, 

 Baroness Schroeder, Albatre, Alba Sulfurea, Mme. Crousse, Mme. Calot, 

 Mme. de Verneville, Boule de Neige, Avalanche, and Due de Wellington. 



Pale Pink. — Achille, Albert Crousse, Dorchester, Floral Treasure, 

 La Perle, Mme. Lemoine, Marguerite, Gerard, Marie d'Hour, Miss 

 Salway, Mademoiselle Leonie Calot, Mme. Emile Galle, and Venus. 



