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cut through these show as a series of stratified tubes. This species is one of the largest and most common of the shelf fungi. It is not found fruiting on living trees as commonly as on the dead ones. The woody shelf varies in size from a few inches to even a foot or more in width, and projects out from the trunk horizontally almost as far. Its upper surface is a light brown and its fruiting surface is white, minutely poroid and easily etched; the tissues within are chocolate-brown. We have found it occasionally on living maples, poplars, willows, apples and peaches, and believe it to be the common heartwood rot of the maple.
Fomes connatus Fr. is a whitish, semi-fleshy or finally somewhat woody, species less than a foot wide and consists usually of several irregular shelving and overlapping brackets. The fruiting surface develops flesh-colored, small, thin-walled pores having a satiny lustre. We have found it fruiting on hickory and hard maple where it caused heartwood rot.
Fomes igniarius (L.) Gill. is a single, woody, roundish to hoofshaped bracket four to eight inches wide. It is at first light brown and smooth above but with age dark brown and more or less concentrically zoned and rimmed. Below, the minutely poroid surface is a rusty-brown color. It has been found on oaks and apples, where it seems to injure somewhat the living tissues as well as cause rot of the wood.
Polyporus squamosus (Huds.) Fr. is a semi-fleshy mushroomlike fungus with a side stem. The upper surface is covered with conspicuous patches of rusty scales and the lower is coarsely poroid. It has been found a few times on living maples where heart rot was present.
Polyporus sulphureus (Bull.) Fr. is a striking species with adhering and overlapping brackets of considerable size that are at first fleshy but on drying corky in texture. The upper surface is orange-red while the lower is a sulphur-yellow with moderate sized pores. While commonly a saprophyte on stumps and logs, at times, it is parasitic on living trees especially, as seen here, on oak.
Polystictus conchifer Schw. is a small, papery, conch-like species found on elm limbs where it produces slow rot and causes the branches to break off easily in storms. Some writers consider it semi-parasitic.
Pleurotis sapidus Kalch., P. ostreaius Jacq., oyster mushroom, and P. ulmarius Bull. are all evident, fleshy, gill fungi of the mushroom type. The two former occur as large, usually clustered or overlapping, brackets with the individual parts narrowed backward to a more or less distinct base down which the gills run for a short distance. The last species consists of a single fruiting body with a much more pronounced stem, arising near the center of the cap, to which the gills are attached by a notch. All are white forms with the tops often more or less brownish, especially toward the center. They are most frequently found on the elm and hard maple and are associated with a heart rot of the wood. All three species are edible.
Hydnum septentrionale Fr. is a very conspicuous but rather uncommon, semi-fleshy when young but leathery when old, bracketed form with the overlapping irregular shelves joined to the trunk by a united but not distinct base. The tops of the shelves are whitish, often somewhat scabrous and the lower fruiting surfaces are differentiated quite markedly from other fungi by the very crowded, pinkish, fine, fruiting spines about half an inch in length. It has been found here, so far, only on hard maple and hickory and is apparently semi-parasitic.
Root Forms: It is not always easy to determine whether roots have been killed by these larger fungi, since the fruiting bodies are rot usually present. Even when either the mycelial threads or the fruiting bodies are seen it is still a possibility that the fungus is a secondary agent following winter or some other injury. The only two species we have found here apparently injuring the roots of ornamental trees are of the toadstool type.
Armillaria mellea (Vahl) Quel. is the most important of the mushrooms attacking the roots of living trees. The umbrella-like cap is usually a honey-yellow with patches of brownish scales; the gills are white and the central stem has a more or less evident ring. They occur in clusters on the ground with the mycelium forming conspicuous, dark colored, rounded strands running over the roots and flattening out under the bark where the woody tissues are invaded. It is more likely to attack coniferous than deciduous trees.
Collybia velutipes Curt. is a yellowish to tawny mushroom, somewhat smaller than the preceding, that is especially distinguished by the velvety brown stems of the clustered fruiting bodies. It is claimed by some to cause injury to the roots of trees though commonly found on dead wood.
Treatment: For further statements concerning the control of wood-destroying fungi, the reader is referred to the articles by Collins and Filley elsewhere in this Report. We shall mention here only the fundamental requirements. The first is the complete removal of all decayed or infected wood and bark to prevent, or at least to arrest, further decay. The exposed wood is usually given an antiseptic and waterproof coating or coatings. The cavity should be properly shaped and the bark so left that rapid callus formation is favored. Whether or not the cavity should be filled is a matter of opinion, but, if filled, there is no question that it should be done properly. This means that the filling should be permanent, semi-flexible, waterproof, non-injurious to the living tissues, especially the cambium layer, tight fitting or better adherent to the wood, and so shaped that the callus readily grows over its exposed surface.
View in Pomfret where trees were broken by ice storm of November 27-30, 1921. This scene also justifies the tree surgeon. Photograph December 6, 1921.
b. Elm tree in Mount Carmel, showing bad pruning. Cavities usually follow such careless work. All cuts should be made close to the trunk or branch. Photograph 1909.
a. Young elm tree in Pomfret, where a large branch had been removed the preceding year. This was a good cut, and healing is well started. Photographed in 1909.
b. The same wound four years later. Photographed in 1913.
c. Large red maple in Bridgeport injured by fire. Cavities were filled with cement concrete in sections.
d. Sugar maple near the preceding, Bridgeport.
The work on both trees was overdone. The bolts were so near together that the cambium died between them.