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Detailed structure of agaric spore prints
Notes and briefarticles ORTON, P. D. (1969). Notes on British agarics, III. Notes from the Royal Botanic Garden, Edinburgh 29, 75-127. PEGLER, D. N. (1977). A preliminary agaric flora of East Africa. Kew Bulletin Additional Series 6, 475477· PEGLER, D. N. & RAYNER, R. W. (1969). A contribution to the agaric flora of Kenya. Kew Bulletin 23, 347412.
179
PILAT, A. (1950). Revision of the types of some extraEuropean species of the genus Crepidotus Fr. Transactions of the British Mycological Society 33, 215249· REID, D. A. (1975). Type studies of the larger Basidiomycetes described from southern Africa, Contributions from the Bolus Herbarium 7, 1-255. SINGER, R. (1975). The Agaricales in modern taxonomy. Edit. 3. Vaduz: J. Cramer.
DETAILED STRUCTURE OF AGARIC SPORE PRINTS C. T. INGOLD
Birkbeck College, London, WC1E 7HX For over a century spore prints have been of interest to agaricologists as indicating the colour of spores in the mass, but there has been little consideration of the prints themselves. Indeed, the only treatment known to me is by Buller (1909). He pointed out that 'the radiating lines correspond to the spaces between the gills'. The comparative freedom from spores of the intervening spaces is due to the fact that the only spores deposited there are those discharged from the gill-edges. This paucity of spores is further emphasized because in most agarics the gill-edge is unproductive. Indeed, the basidia are there frequently replaced, partially or entirely, by cystidia. In agarics, most Russula species constituting a notable exception, the gills are of different lengths.
Fig.
1,
One of medium length is commonly inserted between two full-length gills, and a still smaller gill may occur between each long and medium one. When there are gills of these three lengths, each spore line of the print representing the sector between two long gills (about 12° in Fig. 1) is not a straight one, but traced outwards from the centre dichotomizes twice. This is clearly to be seen in Fig. 1. In preparing a print, if care is taken to place the pileus on a sheet of glass so that the gills are quite vertical and that there is complete freedom from draughts, the resulting spore lines (or spore bands) are not uniformly dense. Each is much denser near the edge so that the band appears to be firmly outlined (Fig. 1). The reason for this is evident. The width of the spore band is determined by
Collybia peronata (Bolt. ex Fr.) Kummer. Spore print collected over a period of 2 h on a glass plate and photographed with transmitted light. x 1·6.
Trans. Br. mycol. Soc. 73 (1) (1979)
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Notes and brief articles
180
the space between opposing gills less twice the distance of spore discharge (0'1-0'2 mm). The spores shot from the horizontal basidia covering the vertical surfaces of the gills fall vertically in still air and outline the spore band. The middle, less dense, region of the band receives spores from the downward-facing hymenium in the arch between the adjoining gills. No doubt the picture is slightly blurred by some unavoidable movement of the air beneath the pileus. The less dense central region of the spore band corresponds to the ' margin of safety'. Buller (1909) pointed out that the distance between gills must exceed the range of spore discharge and that there must be a margin of safety. From the geometry of the agaric sporophore it is obvious that
this margin varies (Ingold, 1971). It is minimal between two opposing gills near the stipe and in the corresponding position in the spore band the delimiting dense lines may run together. On tracing outwards, and before the spore band dichotomizes, the less dense zone, corresponding to the margin of safety, becomes apparent and enlarges up to the point where the middle-length gill is inserted. My thanks are due to Richard Parker for taking the photograph. REFERENCES BULLER, A. H. R. (1909). Researches on Fungi, I. London: Longmans, Green and Co. INGOLD, C. T. (1971). Fungal Spores. Oxford: Clarendon Press.
DISCOMYCETE NOTES AND RECORDS 2 W.D. GRADDON Ross-on-Wye, Herefordshire
ALLOPHYLARIA MACROSPORA (Kirschst.) Nannf., Inoperc, Discom.: 291 (1932). (Fig. 1) The species has been described and figured by Dennis (1956). Recent British collections, on two hosts, have asci to 125 x 13 flm, 8-spored, with a shallow pore, deep blue in Melzer's reagent; spores 22-28 x 5-6 flm, elliptic-fusiform, with polar masses of small guttules, non-septate. Excipulum of strongly phialioid hyphae lying at a low angle to the surface, unstained in Melzer's reagent. Specimens examined: on Chamaenerum angustifolium stems and branchlets of Ulex europaeus, Symonds Yat, Herefords., Septe-Oct. 1977, W. D. Graddon 3170, 3199, 3199a (Ulex).
BELONIUM PSAMMICOLA (Rostr.) Nannf., Inoperc. Discom.: 101 (1932). Apothecia to 550 flm across, superficial, attached by a small central area, dark brown with dark honey disk, contracting to triangular shape when dry. Receptacle vertically striate with serried ranks of dark brown, cylindrical, obtuse hairs to 25 x 7 flm which do not overtop the margin. This characteristic surface is beautifully illustrated by Nannfeldt (op. cit. p. 101). Excipulum pallid, of isodiametric somewhat angular cells to 10 flm across, with rather thick red-brown walls. Asci 40-45 x 5 usu, 8-spored, pore blue in Melzer's reagent. Spores 6-8 x 2 flm. Specimens examined: on Ammophila arenosa, Farr, Trans. Br. mycol. Soc. 73 (1) (1919)
Sutherland, June 1977, R. W. G. Dennis (W.D.G. 3120); Isle of Oronsay, Aug. 1978, R. W. G. Dennis (W.D.G. 3410). DISCOHAINESIA OENOTHERAE (Cooke & Ellis) Nannf., Inoperc, Discom.: 88 (1932). Apothecia to 0'75 rom diam, growing singly or in small groups on the under side of the leaves, pulvinate. Disk creamy, often tinged pinkish. Receptacle amber, very thin at the margin which forms a conspicuous narrow, dark ring round the hymenium. Asci 65-75 x 5-6 flm, 8-spored, pore not blue in Melzer's reagent. Ascospores 8'5-13 x 2-3 usn, fusoid-clavate, continuous. Paraphyses very slender throughout with characteristically branched apices. The species is described and figured by Dennis (1963). Specimens examined: on leaves of Castanea sativa, Ross-on-Wye, Herefords., Oct. 1976, W. D. Graddon (2947); 500-acre wood, Sussex, Sept. 1970 (autumn foray), M. C. Clark (W.D.G. 2181).
PEZlZELLA EPITHALLINA (Phill, & Plowr.) Sacc., Fung. 8: 282 (1889). The species was described and figured by Dennis (1972 ) .
s-n.
Specimen examined: on decaying and discoloured thallus of Peltigera canina, Kerne bridge, Herefords., Feb. 1977,W. D. Graddon 3007.
Printed in Great Britain
0007-1536/79/2828-5310 $00.35 © 1979The British Mycological Society
179
PILAT, A. (1950). Revision of the types of some extraEuropean species of the genus Crepidotus Fr. Transactions of the British Mycological Society 33, 215249· REID, D. A. (1975). Type studies of the larger Basidiomycetes described from southern Africa, Contributions from the Bolus Herbarium 7, 1-255. SINGER, R. (1975). The Agaricales in modern taxonomy. Edit. 3. Vaduz: J. Cramer.
DETAILED STRUCTURE OF AGARIC SPORE PRINTS C. T. INGOLD
Birkbeck College, London, WC1E 7HX For over a century spore prints have been of interest to agaricologists as indicating the colour of spores in the mass, but there has been little consideration of the prints themselves. Indeed, the only treatment known to me is by Buller (1909). He pointed out that 'the radiating lines correspond to the spaces between the gills'. The comparative freedom from spores of the intervening spaces is due to the fact that the only spores deposited there are those discharged from the gill-edges. This paucity of spores is further emphasized because in most agarics the gill-edge is unproductive. Indeed, the basidia are there frequently replaced, partially or entirely, by cystidia. In agarics, most Russula species constituting a notable exception, the gills are of different lengths.
Fig.
1,
One of medium length is commonly inserted between two full-length gills, and a still smaller gill may occur between each long and medium one. When there are gills of these three lengths, each spore line of the print representing the sector between two long gills (about 12° in Fig. 1) is not a straight one, but traced outwards from the centre dichotomizes twice. This is clearly to be seen in Fig. 1. In preparing a print, if care is taken to place the pileus on a sheet of glass so that the gills are quite vertical and that there is complete freedom from draughts, the resulting spore lines (or spore bands) are not uniformly dense. Each is much denser near the edge so that the band appears to be firmly outlined (Fig. 1). The reason for this is evident. The width of the spore band is determined by
Collybia peronata (Bolt. ex Fr.) Kummer. Spore print collected over a period of 2 h on a glass plate and photographed with transmitted light. x 1·6.
Trans. Br. mycol. Soc. 73 (1) (1979)
Printed in Great Britain
0007-1536/79/2828-5310 $00·35 © 1979 The British Mycological Society
Notes and brief articles
180
the space between opposing gills less twice the distance of spore discharge (0'1-0'2 mm). The spores shot from the horizontal basidia covering the vertical surfaces of the gills fall vertically in still air and outline the spore band. The middle, less dense, region of the band receives spores from the downward-facing hymenium in the arch between the adjoining gills. No doubt the picture is slightly blurred by some unavoidable movement of the air beneath the pileus. The less dense central region of the spore band corresponds to the ' margin of safety'. Buller (1909) pointed out that the distance between gills must exceed the range of spore discharge and that there must be a margin of safety. From the geometry of the agaric sporophore it is obvious that
this margin varies (Ingold, 1971). It is minimal between two opposing gills near the stipe and in the corresponding position in the spore band the delimiting dense lines may run together. On tracing outwards, and before the spore band dichotomizes, the less dense zone, corresponding to the margin of safety, becomes apparent and enlarges up to the point where the middle-length gill is inserted. My thanks are due to Richard Parker for taking the photograph. REFERENCES BULLER, A. H. R. (1909). Researches on Fungi, I. London: Longmans, Green and Co. INGOLD, C. T. (1971). Fungal Spores. Oxford: Clarendon Press.
DISCOMYCETE NOTES AND RECORDS 2 W.D. GRADDON Ross-on-Wye, Herefordshire
ALLOPHYLARIA MACROSPORA (Kirschst.) Nannf., Inoperc, Discom.: 291 (1932). (Fig. 1) The species has been described and figured by Dennis (1956). Recent British collections, on two hosts, have asci to 125 x 13 flm, 8-spored, with a shallow pore, deep blue in Melzer's reagent; spores 22-28 x 5-6 flm, elliptic-fusiform, with polar masses of small guttules, non-septate. Excipulum of strongly phialioid hyphae lying at a low angle to the surface, unstained in Melzer's reagent. Specimens examined: on Chamaenerum angustifolium stems and branchlets of Ulex europaeus, Symonds Yat, Herefords., Septe-Oct. 1977, W. D. Graddon 3170, 3199, 3199a (Ulex).
BELONIUM PSAMMICOLA (Rostr.) Nannf., Inoperc. Discom.: 101 (1932). Apothecia to 550 flm across, superficial, attached by a small central area, dark brown with dark honey disk, contracting to triangular shape when dry. Receptacle vertically striate with serried ranks of dark brown, cylindrical, obtuse hairs to 25 x 7 flm which do not overtop the margin. This characteristic surface is beautifully illustrated by Nannfeldt (op. cit. p. 101). Excipulum pallid, of isodiametric somewhat angular cells to 10 flm across, with rather thick red-brown walls. Asci 40-45 x 5 usu, 8-spored, pore blue in Melzer's reagent. Spores 6-8 x 2 flm. Specimens examined: on Ammophila arenosa, Farr, Trans. Br. mycol. Soc. 73 (1) (1919)
Sutherland, June 1977, R. W. G. Dennis (W.D.G. 3120); Isle of Oronsay, Aug. 1978, R. W. G. Dennis (W.D.G. 3410). DISCOHAINESIA OENOTHERAE (Cooke & Ellis) Nannf., Inoperc, Discom.: 88 (1932). Apothecia to 0'75 rom diam, growing singly or in small groups on the under side of the leaves, pulvinate. Disk creamy, often tinged pinkish. Receptacle amber, very thin at the margin which forms a conspicuous narrow, dark ring round the hymenium. Asci 65-75 x 5-6 flm, 8-spored, pore not blue in Melzer's reagent. Ascospores 8'5-13 x 2-3 usn, fusoid-clavate, continuous. Paraphyses very slender throughout with characteristically branched apices. The species is described and figured by Dennis (1963). Specimens examined: on leaves of Castanea sativa, Ross-on-Wye, Herefords., Oct. 1976, W. D. Graddon (2947); 500-acre wood, Sussex, Sept. 1970 (autumn foray), M. C. Clark (W.D.G. 2181).
PEZlZELLA EPITHALLINA (Phill, & Plowr.) Sacc., Fung. 8: 282 (1889). The species was described and figured by Dennis (1972 ) .
s-n.
Specimen examined: on decaying and discoloured thallus of Peltigera canina, Kerne bridge, Herefords., Feb. 1977,W. D. Graddon 3007.
Printed in Great Britain
0007-1536/79/2828-5310 $00.35 © 1979The British Mycological Society