19171 DISEASES OF PLANTS. 851 



Notes on the citrus canker, P. J. Wester (Philippine Agr. Rev. {English 

 Ed.h 9 (1916), No. 2, pp. 155-157).— It is stated that the author first saw citrus 

 canker in the Philippines in 1912 at the Lamao Station, but that he then con- 

 sidered it a virulent form of scab. Though present ever since that time, it 

 caused no serious trouble until after the rainy season of 1914. An account is 

 given of the localities in w^hich it has been noted. What is thought to be 

 citrus canker has been discovered on 22 species or varieties of Citrus in the 

 Philippines as here listed. C. nobilis, C. nobilis papillaris, C. mitis, and C. web- 

 berii montana appear to be practically immune, C. aurantium and C. decumana 

 very variable, and a fev? named are particularly susceptible to citrus canker. 

 The disease is generally most destructive when the plants are less than a 

 meter in height. 



In 1915, the disease was noted in eastern and western Java and in Singa- 

 pore. This fact, its occurrence in the Philippines on some of the most primi- 

 tive Citrus forms, as well as on the native taboc, and its prevalence in China 

 and Japan suggest that the citrus canker may be widespread in Malaysia and 

 perhaps in Indian and Ceylon. 



Diseases of the lime tree, J. B. Habeison, 0. K. Bancroft, and G. E. Bodkin 

 (Jour. Bd. Agr. Brit. Guiana, 9 (1916), No. S, pp. 122-126). — In this report, 

 which deals also with insect pests of limes, mention is made of leaf yellowing, 

 ascribed to soil conditions; staghead, due to constant winds; citrus knot, 

 usually associated here with Loranthus theobromce; gummosis, connected with 

 adverse soil conditions; withertip, leaf spot, or anthracnose, caused by Col- 

 letotrichum gloeosporioides ; sooty mold, consisting of the nonparasitic but in- 

 jurious Capnodium citricolum; a root invasion by Fomes semitostus; a brown 

 root disease, caused by Hymenochcete noxia; lichens on trunks and leaves; 

 and bird vine (L. theobromce). 



A Phoma disease of lavender, W. B. Bbiebley (Roy. Bot. Oard. Kew, Bui. 

 Misc. Inform., No. 5 (1916), pp. IIS-ISI, pis. 2, figs. 9). — A serious disease of 

 Lavandula, apparently confined to this genus, is due to P. lavanduloe, which is 

 here, supposedly for the first time, recorded for England, with an account of 

 a study made by the author on the characters and habits of the causal organism. 

 The mycelium ramifies throughout the tissues of the host, causing collapse of 

 the cortex and phloem groups, the hyphse passing from cell to cell through the 

 abundant pits in the cell walls. The pycnidia form below the epidermis which 

 Is thus lifted from the cortex. Chlamydospores are occasionally formed, but 

 conidia have not been known to occur in the normal life cycle. 



The extension of Marsonia rosae on rose bushes, J. Chifflot (Assoc. Franc. 

 Avanc. Sci., Compt. Rend., 4S (1914), pp. 426-428). — It Is stated that M. rosm, 

 formerly confining its attacks to the foliage, may, in case of certain varieties, 

 extend itself to all the aerial portions of the plant. 



Roesleria pallida, Jessie S. Bayliss-Elliott and W. B. Gbovb (Ann. Bot. 

 [London], SO (1916), No. 119, pp. 407-414, figs. 11).— The authors have made 

 a study of a fungus growing on the roots of a willow which had died at the 

 end of the autumn, 1915, after passing through a period of gradual exhaustion. 

 The fungus supposed to be the cause of the trouble and at first thought to be 

 Pilacre petersii was carefully studied in connection with others supposedly re- 

 lated thereto. 



It is stated that the fungus in question proved to be R. pallida, which is de- 

 scribed, as existing descriptions are considered to require important modifica- 

 tions. It is thought that Pilacre is probably a conidial stage of species of 

 Roesleria (R. pilacriformis being only a slender form of R. pallida and P. 

 petersii being identical with P. faginea). These species of Pilacre are con- 



