Part 43

Fruit-body often frond-like, infrequently shell-shaped and if on birch then small 41

41. Fruit-body fan- or frond-shaped, composed of innumerable more or less complete caps joined together at their base or to half-way Grifola & Meripilus

Fruit-body neither fan-shaped nor frond-shaped and compound 42

42. Fruit-body wholly pale-coloured white, cream, ivory, etc. Tyromyces

Fruit-body except pores usually some shade of brown Polyporus

43. Cap thick, corky or woody and pores medium or large Trametes & Pseudotrametes

Cap thin but leathery and pores small Coriolus

(i) Pored and toothed fungi

(a) Colonisers of tree trunks, stumps and branches

~Polyporus squamosus~ Fries

Scaly polypore

Cap: 100-300 mm. Stem: width 25-50 mm; length 25-75 mm.

Description:

Cap: fan-shaped or semicircular, spreading horizontally with age, ochre-yellow or straw-coloured with dark brown, flattened scales in concentric zones which are much more dense at the centre.

Stem: short, stout, white at apex and netted with pale creamy buff about middle, but dark brown or black towards the base and attached to the side of the cap.

Tubes: whitish to yellowish and decurrent with large, angular, irregularly fringed, whitish or cream-coloured pores.

Flesh: with strong, not very pleasant smell, cream-coloured or white.

Spore-print: white.

Spores: long, oblong or elongate ellipsoid, hyaline under the microscope (10-15 × 4-5 µm) and not blueing in solutions containing iodine.

Habitat & Distribution: An easily recognisable fungus growing on stumps and old living trees, especially of sycamore and elm where it often forms tiers of caps from late spring until autumn; however, they decompose rapidly and almost completely disappear by the next year when new fruit-bodies may appear in the same place, a phenomenon which may take place for several consecutive seasons.

General Information: The genus Polyporus is in most text-books, a big and unwieldy genus joining together all fleshy, annual fungi possessing tubes; even the boleti (see p. 32) have been included! Many of these species are now considered less closely related one to another than previously thought. Boleti differ from polypores, however, in their less tough and distinctly putrescent fruit-body, and in the fact that the margin of the cap extends but does not continue to grow during the life-cycle; the margin of the polypore fruit-body is active and may burst into growth again when favourable weather conditions occur. The ‘Scaly polypore’ has a flesh which consists of two types of hyphae: (i) hyphae of unlimited growth with abundant protoplasmic contents which stain easily and which collapse on drying; and (ii) thick-walled, strengthening hyphae which bind the thin walled hyphae together. Laetiporus sulphureus (Fries) Murrill ‘Sulphur polypore’ has a single type of hyphae in the tubes, i.e. thin walled generative, and only a few binding hyphae in the flesh. It has an orange cap with a rather thick, sulphur or chrome-yellow margin, sulphur-yellow tubes and pores and yellow, then pale buff, flesh. The spore-print is white and the spores hyaline, pip-shaped and medium sized, (5-7 × 4-5 µm).

Illustrations: P. squamosus--F 43^{b}; Hvass 267; LH 75; NB 129¹; WD 94¹. L. sulphureus--Hvass 268; LH 73; NB 129³; WD 94².

Some common annual polypores

~Piptoporus betulinus~ (Fries) Karsten

Birch polypore

Cap: 75-200 mm, kidney-shaped or hoof-shaped, smooth, covered by a thin, separable and greyish silvery or pale brownish skin; cap-margin thick, incurved and projects beyond the tubes.

Stem: rudimentary, simply a small hump below which the fungus develops.

Tubes, pores and spore-print: white.