270 



THE AGRICULTURAL NEWS 



August 19, 191L 



FUNGUS NOTES. 



THE BRACKET FUNGI. 



This group of fungi belongs to the big division known as 

 the Biisidioniycetes, charcterized by the production of t>vo or 

 four spores on a specialized hypha known as a basidium (see 

 Agricultural News, Vol. IX, pp. 94 and 158); the group is 

 called the Polyporaceae. The faKily belongs to the Order of 

 the Hymenomycetes, in which a definite fructification is pro- 

 duced having a special reproductive portion, or hymenium, 

 made up of basidia closely crowded together. In the family 

 in question the hymenium lines the cavity of numer- 

 ous circular or polygonal tubes or shallow depressions 

 in the substance of sporopbores varying much in colour, 

 size, shape and consistency, but all characterized by the 

 occurrence of the tubes lined with the hymenium. 

 The Polyporaceae are closely connected with the Agarica- 

 ceae or toadstool family, in which the hymenium is pro- 

 duced on special gills running radially across the under 

 surface of the sporopLore. In the Polyporaceae, the sporo- 

 phore, or fructification, may be umbrella-shaped like a toad- 

 stool and have a central stalk; or it may possess a stalk 

 attached to one side of the cap; or again the whole sporophore 

 may be stalkless and project at right angles from the substra- 

 tum like a bracket; or, finally, it may lie fiat on the substratum 

 with the hymenium turned upward.?. In the first three cases, 

 the hymenium is always borne on the under surface of the 

 sporophore. As has been stated already, these sporopbores 

 may vary also in consistency ; they may be fleshy, coriaceous 

 or woody, while many of them live for many years and 

 periodically produce a new layer of tubes over the surface of 

 the older layers. The tubes themselves vary largely in width and 

 depth, and the spores they contain may differ in colour. It is 

 by means of these and similar diflferences that the genera 

 and species are separated from one another. 



The family is an important one for two reasons. In the 

 first place, the majority of the species live as saprophytes on 

 wood, and, in consequence, are often responsible for a dry rot 

 of timber. In the second, .some of them, notably members 

 of the genera Polyporus and Fomes, are wound parasites on 

 many diflferent kinds of trees. In the genus Polyporus, the 

 fructification may have a central or lateral stalk, or may 

 occur as a bracket; it is, however, always more or less 

 fleshy when fresh, though it becomes hard when dry. In 

 the genus Fomes, it may have a lateral stalk, or may be in 

 the form of a bracket or hoof, but it is always of a woody 

 consistency from the first. 



In order to illustrate what has lieen said, one or two 

 species may be considered in somewhat greater detail. One 

 very common bracket fungus, both in temperate and tropical 

 countries, is Fomes, lucidus (Leys.), Fr. The sporophore pos- 

 sesses a lateral stalk, which may be as much as 1 inches long, 

 or may be reduced to a broad basal tubercle, so that the fruc- 

 tification appears as a bracket. When the stalk is present 

 it is usually more or less erect, irregularly cylindrical in shape, 

 poli-shed, and varying in colour from bright chestnut to almost 

 black. The apex of the stalk is at first white and conical, 

 but later it grows out into a broad cap or pileus, whose upper 

 surface is yellowish-red, reddish-chestnut, deep red or almost 

 black; it is polished like the stalk, and usually marked with 

 concentric furrows. When the sporophore is immature the 

 margin is swollen, white and fibrous, and is not polished: 

 while the varnished portion immediately behind it is then 

 yellow, and the colour slowly deepens into that of the main 

 part of the cap. The lower surface is white, and contains 



the tubes bearing the brown spores, which are ejected 

 as a dust of the saShe colour. The substance of the sporophore 

 is brown and fibrous. Several caps may fuse together during 

 growth, and their outline then becomes irregular. Single 

 caps are usually circular, or kidney-shaped, when stalked, and 

 semicircular when the stalk is reduced: they vary in size from 

 a diameter of 2 or 3 inches and a thickness of |-inch, to 

 a diameter of 20 or more inches and a thickness of 4 inches. 



This fungus occurs on several trees in temperate count- 

 ries, and has been regarded as a wound parasite on oaks. In 

 Ceylon, it causes root di.sease of the cocoa-nut palm and 

 grows on other palms, while it is associated, as well, with 

 bamboos. It is also known to be parasitic on the roots of the 

 mango and on those of the flamboyante {Poinciana regia), 

 while it is saprophytic on dead stumps of many other trees. 

 (See Fetch. Circulars and A(jricultural Journal of the Royal 

 Botanic Gardens, Ceylon, Vol. IV, No 24.) In India, it has 

 been considered as probably parasitic in several instances 

 on forest trees, while it is lecorded by Butler as the probable 

 cause of a root disease of the areca palm {Areca Catechu). 

 In the West Indies it has been recorded on dead wood, from 

 Trinidad, while Stockdale found it on dead lime trees in 

 Dominica. Kecently. it has been observed in large quantities 

 on dead and dying lime trees, in Montserrat and Antigua, 

 the fructifications being at a height of 6 inches to 3 feet 

 above the ground. The evidence at least suggests that it 

 may have been responsible for the death of the trees. It 

 was also found in the former island on a dead trunk of the 

 hog plum (Spondias lutea), lying among the lime trees. 



Other species of Fomes known to be parasitic in the 

 trojjics are /'. semitostus. Berk., which causes the well-known 

 root disease of Para rubber in Ceylon and Malaya, and 7^. aus- 

 tralis which has been known to cause the death of Acacia 

 decurrcns, in Ceylon. All these species are root parasites, 

 and probably commence their attack by spreading from old 

 tree stumps. 



Another fungus, I'oria hi/polateritia, Berk., causes 

 a root disease of tea in Ceylon. This fungus has a fructifi- 

 cation which is red when mature, and is spread out as a thin 

 crust on the substratum, with the hymenium upwards. It 

 may occur on the surface of the soil near a dead tea bush, 

 or closely adpressed to the dead stem, or partly on both. 

 (See Fetch. Root Diseases of Tea, Circulars and Agricultural 

 Journal of the Royal Botanic Gardens, Ceylon, Vol. V, 

 No. 11.) Like the species of Fomes, it commences its attack 

 from dead stumps. 



Members of the family Polyporaceae appear to be very 

 common in the West Indies. As has been indicated, they 

 vary much in colour, size, shape and consistency, but may 

 all be recognized as belonging to the family by means of the 

 characters given above Several occur in connexion with 

 dead or dying trees in such a way that there is at least 

 a suspicion that they are responsible for the damage observed. 

 A further knowledge of their number.'* and identity would 

 possibly give rise to results of considerable economic 

 imjjnrtance. 



Mr. F 



DEPARTMENT NEWS. 

 W. South, h!.A., Mycologist on the Staff of 



the Imperial Department of Agriculture, returned to 

 Barbados by tl« R.M.S. 'Atrato', on the 9th instant, 

 from the Northern Islands, where he had been making 

 investigations into the fungus diseases of various crops. 



