792 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Persimmon * Ormond * {U.S.A. Dep. Agr., Year Book 1912, 

 p. 270 ; col. plate). — A recent variety of uncertain origin having the 

 property of keeping remarkably late. — E. A. Bd. 



Pescatoria. By A. Malmquist (Orchis, vol. vii. pt. vii. pp. 108- 

 109). — Orchids of the Pescatoria group have been grown with success 

 on blocks of Acacia. The rough side of the block is covered with 

 a thin layer of fresh Sphagnum, on which the orchid is placed and 

 the whole is fastened with wire to an earthenware plate. A porous 

 compost of equal parts of charcoal, fibrous peat, and Sphagnum is piled 

 up on the plate, which is suspended close to the glass, in a house with 

 a moist atmosphere. In summer a temperature of 64 0 F. in the 

 shade or 73 0 F. in the sun is desirable, and 55 0 F. in winter. Frequent 

 watering should be avoided. — 5. E. W. 



Pilocereus Straussi Hesse. By E. Hesse (Gartenflora, vol. 

 lxii. pt. xvii. pp. 383-384; 1 fig.). — This Bolivian cactus loses its 

 woolly covering in cultivation and is clad with spines resembling spun 

 glass in appearance. — S. E. W. 



Pinus Malletti. By S. Mottet {Rev. Hort. pp 263-266, June 1, 

 I 9 I 3 \ 3 ill.) . — Apart from a description of this species the illustra- 

 tions are of interest as showing how magnified sections of the leaves 

 of conifers are capable of determining one closely-allied species from 

 another by the special arrangement of the resin-bearing vessels within 

 them.— C. T. D. 



Pith-ray Flecks in Wood. By H. P. Brown (U.S.A. Dep. Agr., 

 Forest Service, Circ. 215, May 7, 1913). — Investigations have con- 

 clusively proved that the so-called pith flecks are caused by the larvae 

 of a dipterous insect living in the cambium of the wood during the 

 growing season. These flecks or spots often render the lumber unfit 

 for certain uses. Some excellent illustrations are given of timber 

 affected by pith flecks, for which no real remedy has yet been discovered. 



A. D. W. 



Plant, Skin Irritating (Agr. Gaz. N.S.W. vol. xxiv. pt. ix. p. 778).— 

 Gingko biloba, the Maiden-hair tree, must be added to the list of plants 

 which may attack the skin. Some' persons suffer from a red rash 

 after handling the fruit.— S. E. W. 



Plum 'Laire' {U.S.A. Dep. Agr., Year Book 1911, p. 430 ; col. 



plate). — Considered a form of Prunus orihosepala brought into culti- 

 vation about 1876. A small red fruit which would not be considered 

 worthy of cultivation in Europe, but largely grown in Kansas. 



E. A. Bd. 



Plum 'Moncelt* (U.S.A. Dep. Agr., Year Book 1911, p. 432; 

 col. plate). — A seedling from a Japanese variety, and ' Clyman ' a 

 domestica form. Has the tri flora form and foliage. Valued for 

 shipping qualities and resistance to some diseases. — E. A. Bd. 



