Macrophomina Phaseoli (Maubl.). Ashby 147

(II) PETRAK, F. Mykologische Notizen, 289. Ann. Mycol, XXI (1923), 314-315.(12) SYDOW, H. and P., and BUTLER, E. J. Fungi Indiae orientalis, Ann.

Myco!. XIV (1916), 187.(13) Anonymous. A new fungus pest of beans. Science, N.S. LXIV (1926), 10,

No. 1655.(14) Plant Disease Reporter (Bur. Plant Ind. U.S. Dept. Agric. IX (1925), 60;

X (1926), 18,59,81, 120.)(15) MAUBLANC, A. Bull. Soc. Myc. France, XXI (1905), 90.(16) PETRAK, F. and SYDOW, H. Die Gattungen der Pyrenomyzeten, Sphae­

ropsideen und Melanconieen (1926), I Teil, I Lief, II3-I26. (Reper­toriurn specierum novarum regni vegetabilis, XLII, I Beihefte.)

(17) -- -- Ann. Mycol. XXIII (1925),226.(18) MARTIN, W. H. Sclerotium bataticota-the cause of a fruit rat of peppers.

Phytopath. VII (1917), 3°8-312.(19) SMALL, W. Sclerotium bataticola Taub. Trap. Agric. (Ceylon), LXVII

(1926), NO.2.(20) -- Rhizoctonia bataticola (Taub.) But!. Trap. Agric, LXVII (1926),

NO·4·(21) FINLOW, R S. Rhizoctonia in jute. Agric. Journ. India, Science Congress

Number (1918), pp. 65-72.(22) JACOB. Effect of potash fertilisation on the stem-rot of Chinese jute.

Erniihrung der Pftanze, xx (1924), 146-147. (Abs. in Rev. Appl. Myc.IV (1925),35-36.)

THE HOST PLANTS OF FOMES ANNOSUS.By Malcolm Wilson.

THE Red Rot or Heart Rot caused by F omes annosus has beenlong recognised in this and in other countries of WesternEurope as one of the most important diseases of conifers. Inthis country the disease has assumed increasing importanceduring recent years on account of the extensive schemes ofafforestation which are being carried out, and any facts regardingits distribution and biology are consequently of importance.

In this country M. L. Anderson (I, 2) has recently recorded itsoccurrence on the following coniferous species: Pinus sylvestris,Picea excelsa, P. siichensis, Larix europaea, L. leptolepis, Tsugaalbertiana, Abies grandis, Thuya gigantea and PseudotsugaDouglasii.

To this list must be added Pinus Laricio, Abies nobilis andA. pectinaia, and it appears probable that all coniferous speciesmay be attacked. It has not been observed on Pinus Strobusin this country but has been recorded on this species by Hartig (3)

and on Abies balsamea by Tubeuf un. Its occurrence on Juni­perus communis also has been reported by Hartig «3), p. r86) inGermany, and recently the fungus was found attacking thisspecies in Scotland.

Fomes annosus appears to be chiefly a European species, foralthough it has been recorded in North America on Pinusmonticola and other conifers, its occurrence there appears to beunusual and it docs not seem to be of any importance as the

148 Transactions British Mycological Society

cause of disease in the United States (8, ro , 12). Practically allthe American conifers that have been introduced into thiscountry have been seriously attacked by the disease, and thefact may perhaps be explained on the supposition that theAmerican fungus differs at least physiologically from theBritish species.

There is no doubt that Fomes annosus does occur on aconsiderable number of dicotyledonous trees and shrubs but itsdistribution on these hosts appears to differ considerably in thedifferent countries of Europe. Lind ((5), p. 386) in Denmarkrecords it on eleven dicotyledonous species including QuercusRobur, Fraxinus excelsior, Fagus sylvatica, Betula alba, Prunusavium, Pyrus Aucuparia, Ulmus montana and Calluna vulgaris.On the other hand, Lagerberg (4) states that he has been unableto find any attack on dicotyledonous trees in Scandinavia. InGermany, however, it has been recorded on Betula alba (3),

Corylus Avellana and Alnus glutinosa ((9), p. 6r), Acer sp.((7), p. 422) and on Fagus sylvatica and Craiaegus Oxyacantha((II), p. 450), while Prillieux ((6), T. I, p. 325) mentions it on fivedicotyledonous species including Quercus Ilex, although it is notclear that his list refers especially to France. It has beencollected on various deciduous trees in North West America (rz).

I ts distribution on dicotyledons in Scotland appears to befairly similar to that in France, Germany and Denmark; it hasbeen found on the following species: Fagus sylvatica, Betula alba,Corylus Avellana, Alnus glutinosa, Prunus Padus, Pyrus A ucu­paria, Pyrus Aria, Crataegus Oxyacantha and Rhododendronponticum var. Up to the present it has not been found onCalluna vulgaris in this country and this fact may be of import­ance, especially in Scotland where heather is found over wideareas which are suitable for afforestation. Its occurrence onRhododendron ponticum which is so commonly found in planta­tions may be also a fact of considerable significance.

The importance of the occurrence of Fomes annosus uponangiosperms rests on the assumption that the fungus fromthem can infect conifers. No experimental work appears tohave been carried out on this point and until it is done thequestion must be left open.

It is well known that coniferous plantations formed on whatwas previously arable ground are often severely attacked byFomes annosus and the origin of the fungus in these cases hasbeen somewhat difficult to explain, especially when the planta­tions are at some distance from other coniferous woods. Thefact that the fungus can grow on a number of dicotyledonoustrees, among which are several common hedgerow species, seemsto offer a possible explanation. Its occurrence on oak and birch

Hosts of Fomes annosus . Malcolm Wilson 149

may explain the frequent appearance of the disease when scrubareas, covered by these species, are cleared and planted up withconifers.

I wish to thank Dr A. W. Borthwick and Messrs JamesFraser and J. Macdonald of the Forestry Commission andDr M. L. Anderson and Messrs G. Leven and J. S. L. Waldiewho have kindly supplied me with information on this subject.

REFERENCES.

(I) ANDERSON, M. L. Soil Conditions affecting the Prevalence of Famesannosus iTrametes radiciperdas. Trans. Roy. Scot. Arbor. Soc. xxxv(1921), II2.

(2) -- Heart Rot in Conifers. Trans. Roy. Scot. Arbor. Soc. XXXVIII(19 24), 37·

(3) HARTIG, R. The Diseases of Trees. Eng. Trans. London, 1894.(4) LAGERBERG, T. Rotomas Betydelse for Granen och dess Avkastning.

Skogs. For. Tids. H. II-I2 (1923), 313.(5) LIND,]. Danish Fungi. Copenhagen, 1913.(6) PRILLIEUX, E. Maladies des Plantes agricoles. Paris, 1895.(7) !{ABENHORST, G. L. Deutschlands Krytogamen Flora. I. Leipzig, 1844.(8) I{ANKIN, W. H. Manual of Tree Diseases. New York, 1918.(9) l{OSTKOVIUS, F. W. T. In Sturm, Deutschlands Flora. IV. Die Pilze

Deutschlands, Niirnberg, 1838.(IO) SCHRENK, H. VON. Some Diseases of New England Conifers. U.S. Dept.

Agric., Bull. 25, 1900.(II) TUBEUF, C. VON. Diseases of Plants. Eng. Trans. by W. G. Smith,

London, 1897.(12) WEIR,]. R. Notes on Wood-destroying Fungi which grow on both coni­

ferous and deciduous trees. Phytopathology, IV (1914), 275.(13) WEIR, ]. R. and HUBERT, E. E. A Study of the Rots of the Western

White Pine. U.S. Dept. Agric. non. 7(j<j, 1919.

THE RATE OF GROWTH OF LICHENS.

By L. Porter, M.5c., University College, Cork.

RECENT work on the rate of growth of lichens has been sum­marised by Miss Lorrain Smith in the Transactions for 1923and 1925. Linkola's work on species of Parmelia, growing onpalings, showed the average rate to be I mm. per annum. Thisis exceeded by P. cenirifuga on rocks, with a rate of 2'5 mm. perannum.

From these measurements the ages of different specimenswere deduced, e.g. P. sulcata, 30-40 years; P. centrifuga, 50-80,

On the other hand, Tobler, in examining species of Cetraria onbeech and spruce, found that the rate of growth was I em. perannum.

Miss Lorrain Smith points out that Tobler was dealing withyoung plants, often composite forms from the mingling of