770 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



"Caltrop" {Trihulus terrestris). By H. 0. L. Anderson {Ayr. 

 Gaz. N.S.W. vol. xxi. pfc. v. pp. 442-443; 5 figs.). — This dangerous 

 weed creeps on the ground, and bears yellow flowers with five petals. 

 The fruit is hard and is provided with five spines, which can lame horses 

 and other animals. — S. E. W. 



Canker ** New York": Occurrence in England. By E. S. 



Salmon {Gard. Chron., No. 3617, April 1910; fig.).— This canker, due 

 to Sphaeropsis malorum, has been found in the branches of a pear-tree 

 growing in Surrey. The disease can be distinguished from the injury 

 caused by the scab fungus [Venturia pirina) in two- or three-year-old 

 wood of some varieties of pear, by the marked cracking of the bark^ 

 the formation of incipient " cankers," and by the absence of the pock- 

 like markings so characteristic of pear scab. This injury is not so 

 deeply seated as the true canker due to Nectria ditissima. 



Treatment with Bordeaux mixture is recommended. — A. S. H, 



Canker" of Apple Trees Caused by the "Brown Rot" 

 Fung-US. By E. S. Salmon {Gard. Chron., No. 3621, May 1910; 

 fig.).-— The fungus Sclerotinia fructigena, in its conidial or Monilia 

 stage, has long been known as the cause of the " Brown Eot " disease 

 of certain fruit-trees, while the mycelium can invade and kill the wood 

 of the cherry,., plum, and peach. The author states that this fungus, 

 under certain circumstances, causes a canker in apple-trees, which is 

 always situated in the neighbourhood of a fruit spur. Infection of the 

 branch is brought about in the following manner: Apples attacked by 

 the " Brown Eot " fungus may remain in the tree during winter, and 

 in some cases, when rotting, press against the part of the branch near 

 the spur on which they were borne; thereupon the mycelium perie- 

 .trates from the diseased apple into the branch, causing local injuries 

 of a, more or less cankerous nature. Again, a canker may arise by the 

 mycelium invading the wood from a fruit spur which has become 

 diseased through its flower or fruit being attacked. 



The .disease is hable to occur only on certain varieties of apple. 



Spraying with Bordeaux mixture is recommended just before the 

 flower-buds open, and again directly the bloom has set. — A. S. H. 



Cattleya *Princesse Elitna.' By G. T. Grignan {Rev. Hort., 

 May 16, 1910, pp. 228-229 ; col. plate).— The plate represents a very 

 beautiful, fqrm dei^ived from 0. Mossiae Reineckeana x C. aurea. 

 Petals and sepals pure white, labellum wide, with crenate, crispate 

 edges, rich yellow mou,th with magenta stripes blending towards the 

 edge into a magenta ipargin with lighter edging.— C. T. D. 

 "* ' Cereus tricostatus E. E.-G. By Eoland-Gosselm (Eev. Hori., 

 Jan. 16, 1910, pp. 28-29; 1 illus.).— Highly recommended as a hand- 

 some climbing Cereus suitable for growing in soil in a cold green- 

 house. Flowers successively from April to November if the roots be 

 ■guarded from frost; flowers very large; fruit deep crimson, weighing 

 over a pound.— C. T. D. 



