Species of Agaricus occurring in New Zealand

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1 New Zealand Journal of Botany ISSN: X (Print) (Online) Journal homepage: Species of Agaricus occurring in New Zealand A. D. Mitchell & M. Walter To cite this article: A. D. Mitchell & M. Walter (1999) Species of Agaricus occurring in New Zealand, New Zealand Journal of Botany, 37:4, , DOI: / X To link to this article: Published online: 17 Mar Submit your article to this journal Article views: 418 Citing articles: 5 View citing articles Full Terms & Conditions of access and use can be found at

2 New Zealand Journal of Botany, 1999, Vol. 37: X/99/ $7.00 The Royal Society of New Zealand Species of Agaricus occurring in New Zealand A. D. MITCHELL Ecology and Entomology Group Soil, Plant and Ecological Sciences Division P.O. Box 84 Lincoln University Lincoln, New Zealand M. WALTER The Horticulture and Food Research Institute of New Zealand Canterbury Research Centre P.O. Box 51 Lincoln, New Zealand Abstract A key is provided for 21 species occurring in New Zealand: Agaricus arvensis,a. augustus, A. bambusae var. australis, A. bernardii, A. bisporus var. bisporus, A. bitorquis, A. campestris var. campestris, A. campestris cf. var. floccipes, A. cupreobrunneus, A. horakii, A. impudicus (= A. variegans),a. lanatoniger, A. lanipes,a. meleagris, A. oligocystis, A. porphyrocephalus, A. purpureoniger, A. semotus, A. subperonatus, A. viridopurpurascens, and A. xanthoderma. Full descriptions are given for those taxa encountered by the authors in the field, including 10 species which are considered cosmoplitan in distribution. Six of these species are new records for New Zealand. Keywords Agaricales; Agaricus; mushroom; New Zealand; systematics; taxonomy B98070 Received 21 December 1998; accepted 23 August 1999 INTRODUCTION The genus Agaricus is generally described as having white, yellow, or brown pileus; free lamellae with regular trama when young, later becoming irregular; and purple-brown to dark brown spore print, basidiospores smooth with a compound wall not visibly pseudoamyloid. The monographs of Agaricus species most commonly referred to are those of Schaffer & M611er (1938), Moller (1950,1952), Pilat (1951), Heinemann (1978, 1986), Cappelli (1984), and Wasser( 1989). Heinemann's (1978,1986) treatment of Agaricus ranked species traditionally included in the genus (mostly cosmopolitan) at subgeneric level. He erected two additional, predominantly subtropical and tropical subgenera, Langagaricus and Conioagaricus (the latter proposed to be closely related to Micropsalliota). A total of 21 Agaricus species have been recorded from New Zealand (Table 1), including four from the subgenus Langagaricus and two from the subgenus Agaricus (Heinemann 1974). Most species of Agaricus are edible, with A. bisporus the most extensively cultivated mushroom in the world; the major regions of cultivation are Europe, North America, China, and Australia. However, A. xanthoderma and A. meleagris, which are known to occur in New Zealand (Taylor 1981,1983), form part of a group that can cause gastrointestinal upset, the toxic principles including phenolic metabolites (Bresinsky & Besl 1990; Gill & Strauch 1984). Many of the records of Agaricus species occurring in New Zealand come from the work of Taylor (1970,1981, 1983) (Table 1). Her paintings provide clear detail and her publications have proven to be the most popular source of information on fungi in New Zealand. Species described by Heinemann (1974) are presently considered endemic to New Zealand. All other species of Agaricus found in New Zealand are generally recognised as cosmopolitan with a global distribution, e.g., Europe, Asia, Africa, North America, South America, Caribbean, Pacific region, Australia, and Madagascar (Wasser 1989). Given the

3 716 New Zealand Journal of Botany, 1999, Vol. 37 distribution of species such as A. bisporus and A. bernardii in widespread and remote parts of New Zealand, it would seem reasonable to hypothesise that at least some of the cosmopolitan species found here are indigenous. However, the limited distribution and associations of species such as A. augustus (Ridley 1995) anda. lanipes suggest that some species have become naturalised in New Zealand. Definitions of species relationships within Agaricus have been based mainly on morphological and macrochemical characters, especially those of reproductive structures. This has been problematic as it is difficult to objectively determine discrete characters for use in the systematics of this genus, not only due to the simple gross morphology but also because of environmentally and developmentally induced character variation. The search to increase the quantity of data available for assessment of Agaricus species relationships has lead to the use of computer-based analyses and molecular methods. Application of image analysis by Mitchell et al. (1997) provided new variables for studies of basidiospores, including area and circularity as well as length, breadth, and elongation. Principal component analysis of these continuously variable quantitative characters allowed estimates of species groups by Mitchell et al. (1997) but did not necessarily provide information onphylogenetic relationships. Better definition of the variability within and between Agaricus species through increased sampling is needed. The application of data-coding procedures such as segment coding (Chappill 1989) might be used to transform basidiospore data for phylogenetic analyses. Parsimony and maximum likelihood analyses of nuclear ribosomal DNA sequence data by Mitchell & Bresinsky (1999), have allowed the generation of phylogenetic hypotheses for species of Agaricus. They found two well supported clades. The Agaricus Glade containeda. subperonatus,a. devoniensis, A. bisporus, A. spissicaulis, A. bitorquis, and A. impudicus. Their results suggested that A. bernardii may be closely related to this group. The Arvenses Glade contained A. silvicola, A. arvensis, A. abruptibulbus, and A. semotus. They proposed A. lanipes and A. maskae as a possible sister group to the Arvenses Glade. Further work is needed to increase the number of representatives for each species and assess the phylogenetic position for members of Heinemann's (1978, 1986) subgenera Langagaricus and Conioagaricus, including those species in New Zealand. The objective of this study is to provide a key to the New Zealand species of Agaricus plus descriptions of 10 species which we have encountered in the field, as an aid to their identification in this Table 1 Species of Agaricus recorded from New Zealand. Species A. arvensis (J.Schff.) Fr. A. augustus Fr. A. bambusae var. australis Heinem. A. bernardii Qua. apud Cke. & Qua. A. bisporus var. bisporus (J.Lge) Imb. A. bitorquis (Quel.) Sacc. A. campestris var. campestris (L.) Fr. A. campestris cf. var.floccipes (Moll.) Pil. A. cupreobrunneus (Moll.) Boh. A. horakii Heinem. A. impudicus (Rea) Pil. (=variegans) A. lanatoniger Heinem. A. lanipes (Moll. & J.Schff.) Sing. A. meleagris (J.Schff.) Imb. A. oligocystis Heinem. A. porphyrocephalus Moll. A. purpureoniger Heinem. A. semotus Fr. A. subperonatus (J.Lge) Sing. A. viridopurpurascens Heinem. A. xanthoderma Gen. References Taylor (1970, 1981) Ridley (1995) Heinemann (1974), Taylor (1981) New record for NZ New record for N Taylor (1981) Taylor (1981, 1983) New record for NZ New record for NZ Heinemann (1974) Taylor (1981) Heinemann (1974) New record for NZ Taylor (1981) Heinemann (1974) Taylor (1983) Heinemann (1974), Taylor (1981) New record for NZ Taylor (1970, 1981) Heinemann (1974) Taylor (1983)

4 Mitchell Agaricus in New Zealand 717 country. Part of this work was carried out during the preparation of a thesis on Agaricus phylogenetic relationships based on allozyme and basidiospore data (Mitchell 1994). METHODS Standard mycological methods (e.g., as described by Heinemann (1978, 1986), Cappelli (1984), and Wasser (1989)) were used for the examination of specimens described here. The Schaffer's crossreaction involves making intersecting streaks of aniline and concentrated nitric acid (HNO3) across the pileus surface. The point where the two lines intersect may be positive (changes to orange or fire red) or negative (no colour change). The alkali test involves the application of strong KOH to the pileus surface and may be positive (changes to yellow or orange) or negative (no colour change). Microscopic characters were based on observations made using 5% aqueous KOH, Melzer's reagent, or Lactophenol Cotton Blue as mountants (Cruickshank et al. 1965; Singer 1986). Data on basidiospores given in descriptions were derived from image analysis (Mitchell et al. 1997) of between 100 and 300 basidiospores from each of three specimens of each species. These measurements fitted within the range of previously published data (e.g., Cappelli 1984; Wasser 1989). Colour codes and terminology are from Munsell (1967). Definition of colour may be very subjective and factors such as environment and development may have profound influence over the colour of basidiomata. Depending on environmental conditions, it is possible for all species described here to produce basidiomata both in the spring and autumn. Most collection was carried out in Canterbury and was not part of a concentrated national survey. This implies that a great many more Agaricus species might yet be found in this country. Map references are from New Zealand Map Series (NZMS) 260. Herbarium specimens are lodged at Landcare Research, Private Bag 92170, Auckland (PDD). Characters for species not described here but included in the key have been checked on herbarium specimens: A. augustus (PDD 29038, 32385, 70352); A. bambusae var. australis (Type: PDD27102); A. horakii (Type: PDD27106); A. lanatoniger (Type: PDD27107); A. oligocystis (Type: PDD27104); A. purpureoniger (Type: PDD27105); A. viridopurpurascens (Type: PDD27103); A. xanthoderma (PDD25624, 25625, 25626, 25739, 28852, 44827); A. impudicus (=variegans), A. Bresinsky & B. Wittmann-Bresinsky 224, Apr 1995, Paihia, Bay of Islands, New Zealand. This specimen of A. impudicus is held at the Institute for Botany, Regensburg University, D-93053, Regensburg, Germany. Herbarium material for A. meleagris was not seen. KEY TO AGARICUS SPECIES IN NEW ZEALAND Subgenus Agaricus Basidiomata fleshy; general veil not woolly or detersile, usually poorly developed on pileus; pileus smooth or with fibrils or scales, sometimes cracked, epicutis without removable elements, margin not striped. Two groups may be separated. Basidiomata bruising reddish, rarely yellowing; general veil is usually well developed and forms a complex annulus with the partial veil; annulus may be formed mainly from the partial veil (often poorly developed); stipe usually cylindrical, solid, or hollow; Schaffer's cross-reaction negative; KOH test negative; odour fungal and never of anise or of almonds; basidiospores may have apical pore. Group 1 Basidiomata bruising yellowish; general veil poorly developed, usually reduced to flakes or strips on the lower surface of the annulus and the lower part of the stipe; partial veil usually well developed, forming a membranous annulus; stipe often bulbous and spindly, hollow, rarely solid; Schaffer's crossreaction usually positive, may be negative; KOH test positive; usual to have odour of anise or of almonds, but may be unpleasant of phenolic, ink, turpentine, or carbolic acid; basidiospores without apical pore. Group 2 Key to Group 1 1 Lamellae edges fertile, lacking cheilocystidia, concolorous; basidiospores ellipsoid 2 Lamellae edges sterile, well-developed cheilocystidia; basidiospores globose 5 2 Pileus usually white; basidiospores with apical pore (may be rudimentary) 3 Pileus not white or with yellowing; basidiospores with no apical pore 4

5 718 New Zealand Journal of Botany, 1999, Vol Pileus mm diam., becoming convex-applanate, surface silky smooth, bruising red; stipe cylindrical, narrowing at base l.a. campestris var. campestris Pileus mm diam., becoming convex, often centrally depressed, surface scaly in centre, streaked towards the margin, white when young, latter yellowish. stipe pointed at the base, sometimes twisted, yellow below annulus, bruising yellow 2. A. campestris cf. \zr.floccipes 4 Pileus dark purple-brown scales on lilac surface, scales decreasing towards the margin, bruising dark red; stipe woolly, with brown under the annulus 3. A. porphyrocephalus Pileus with dense light brown scales at centre, decreasing towards margin, brown to reddish on bruising; stipe smooth, brownish below annulus, surface f l o c c o s e 4. A. cupreobrunneus 5 Flesh on cutting or bruising becoming intensively red or carmine red. Pileus scaly or fibrillose 6 Flesh gradually becoming reddish-brown when cut or bruised, (this change may occur mainly in the stipe) 7 6 Stipe length usually less than pileal diameter; pileus mm diam., hemispherical when young, finally broadly convex-applanate, ± centrally depressed, surface with broad scales, sometimes becoming very pronounced during dehydration, whitish when young, finally brownish; colour change quickly to strong red when cut or bruised; odour unpleasant, offish or algae 5. A. bernardii Stipe length as much as double the pileal diameter; pileus mm diam., fibrillose, thick, fibrillose; flesh changing colour when cut or bruised notably in the pileus and stipe apex areas; odour not of fish or algae A. impudicus (=variegans) 7 Basidia predominantly 2-spored, (rarely 1-, 3-, or 4-spored). Usually developing above the soil or humus; pileus 50-80(-120) mm diam., convex, brown scales on white surface; margin thick 6. A. bisporus var. bisporus Basidia predominantly 4-spored. Basidiomata often developing largely beneath the surface of the soil or humus 8 8 Pileus (40-)90(-150) mm diam., very thick, fleshy, hemispherical when young, finally broadly convex to applanate, surface smooth to streaky, reddish brown to brown, with fibrillose scales l.a. subperonatus Pileus (30-)50(-70) mm diam., convex when young, fmally broadly convex-applanate, surface silky to fibrillose, white when young, bruising ochraceous brown 8. A. bitorquis Key to Group 2 1 Odour anise or almonds; basidiomata yellowing to browning on pileus and stipe when bruised or exposed (not usually restricted to the base of the stipe), rarely reddening, general veil crumbly, often forming flakes at the base of the annulus 2 Odour unpleasant, has been described as phenolic, ink, turpentine, or carbolic acid; basidiomata often with intense yellowing when bruised at the base of the stipe and veil; may cause stomach upsets Mature basidiomata thick and fleshy; pileus may be large, mm diam.; Schaffer's cross-reaction positive or negative 3 Mature basidiomata not thick and fleshy; pileus small, mm diam.; Schaffer's cross-reaction positive 5 3 Pileus white, mm diam.; Schaffer's cross-reaction positive 9. A. arvensis Pileus not white, mm diam.; Schaffer's reaction positive and/or negative 4 4 Pileus mm diam. globose, surface orange-brown, or dark orange, fibrillose, appressed, concentric scales; when broken or bruised usually becoming yellow, but may show pinkish red towards the base of the stipe and above the annulus. Schaffer's cross-reaction positive A. augustus Pileus mm diam., fleshy, convex when young, then convex-applanate, sometimes with a depressed centre, moderate brown to dark brown scales on paler surface; reddening reaction when bruised or broken, but may show yellowing towards the base of the stipe; Schaffer's cross-reaction usually negative 10. A. lanipes 5 Pileus mm diam., fawn scales on white background at centre, decreasing towards margin II. A. semotus Pileus mm diam., not with fawn scales 6

6 Mitchell Agaricus in New Zealand Pileus with flat-lying fibrillose scales, brown to reddish purple on a whitish background, surface dry; basidiospores x µm, sometimes with thinning apex such that it looks like apore A. bambusae var. australis Pileus dark brown with olive glow; scaly on a clear background, covering viscous when in humid state; basidiospores x 3.5^.1 j.m, no apical pore A. viridopurpurascens 7 Pileus greyish ochraceous brown or clay brown, in the centre with dark brown, appressed scales; bruising dull yellow, including towards the base of the stipe A. meleagris Pileus white or grey-brown towards the centre, bruising yellow, glabrous, smooth, silky, may be covered with cracks or fissures, radially towards the margin; flesh bright chrome yellow towards the base of the stipe, especially with bruising A. xanthoderma Subgenus Langagaricus General veil usually woolly and/or detersile, well developed on the pileus, consisting of elongated and often multiseptate hyphae, sometimes scaly, (also on lower part of stipe), epicutis with removable elements. 1 Pileus and stipe base dark brown to chocolate brown, may have purple glow; lamellae edges infertile; Schaffer's reaction negative 2 Pileus red ochre; Schaffer's cross-reaction positive; lamellae edges fertile with basidia A. oligocystis 2 Basidiomata stocky; annulus fragile. A. horakii Basidiomata slender; annulus membranous Pileus and base of stipe dark brown; basidiospores (6.5) x µm A. lanatoniger Pileus and base of stipe dark brown with purple glow, scales velvet-like and flat lying; basidiospores x (3) j.m A. purpureoniger SPECIES DESCRIPTIONS 1. Agaricus campestris var. campestris (L.) Fr. Fig. 1 Pileus mm diam., medium thickness, fleshy, spherical when young, finally convex-applanate, surface silky smooth, white (N9.5) when young, finally pinkish (5R 8/4), bruising red (5R 6/10-4/12); margin inrolled when young, finally straight, with remnants of veil; lamellae insertion free, thin, crowded, pale pink (5R 9/2) when young, finally stronger pink (5R 8/4) then brown (5YR 4/4); edge concolorous, fertile; trama parallel to irregular. Stipe x mm, central, solid, cylindrical, narrowing at base, surface smooth, floccose at apex, white (N9.5), bruising reddish (5R 6/10-5/10). Annulus thin, wide, pendant, brownish (5YR 4/4) above, white below, surface silky. Flesh white (N9.5), quickly reddening (5R 6/10-4/12) upon cutting or bruising; odour and taste pleasant. Schaffer's cross-reaction negative. Basidia 4-spored, x µm, broadly clavate, with sterigmata 2-5 p.m. Basidiospores dark brown (5YR 3/2) in mass, size (7.1-)8.0(-8.9) x (4.8-)5.5(-6.1)µm, elongation (1.3-)1.5(-1.7)µm, ovoid to ellipsoid, brown (2.5YR 4/4) in water, refractive centre (1-2 droplets), apiculus lateral, germpore present. HABITAT: Common in rings in lawn or pasture. NEW ZEALAND DISTRIBUTION: Auckland (Taylor 1983), Canterbury, Fiordland. SPECIMENS EXAMINED: CANTERBURY: Lincoln University, biological husbandry area, NZMS 260 M36/66-29-, PDD 69634, 52394, 53383, 62028, 28851, A. campestris cf. var.floccipes (Moll.) Pi1. Pileus mm diam., medium thickness, fleshy, spherical when young, then convex, often centrally depressed, surface scaly in centre, streaked towards the margin, white (N9.5) when young, later moderate yellow-orange (10YR 8/10-7/10). Stipe x mm, very pointed sometimes twisted base, creambuff below annulus (2.5Y 9/2), bruising yellow (10YR 8/10). Annulus thin, pendant, often flocculose. Flesh becoming pale brown (5YR 6/4-5/6) upon cutting or bruising. Basidia 2-4-spored, x 6-9 p.m, clavate, sterigmata 3 5( 10) µm. Basidiospore size (6.7-)8.2(-9.3) x (5.1-)5.8(-6.5) µm, elongation (1.2-)1.4(-1.6) µm, ellipsoid. HABITAT: Common in rings in lawn or pasture. Good edible quality. NEW ZEALAND DISTRIBUTION: Canterbury. SPECIMENS EXAMINED: CANTERBURY: Halswell, SE of Sabys Rd, NZMS 260 M36/74-34-, PDD 68570,

7 720 New Zealand Journal of Botany, 1999, Vol. 37 Fig. 1 A, A. bisporus var. bisporus; B, A. bitorquis; C, A. campestris var. campestris; D, A. subperonatus. Bars = 5 gm. 3. Agaricus porphyrocephalus Moll. Fig. 2 Pileus mm diam., thick, fleshy, convex when young, finally broadly convex, often with central depression, dark red-purple (5R 4/4-3/2) scales on lilac surface, scales decreasing towards the margin, bruising dark red (5R 4/8); margin inrolled when young, finally inrolled to straight, uneven edge, with remnants of veil; lamellae insertion free, thin, crowded, pink (5R 4/4-6/4) when young, finally reddish brown 5R 3/2); edge concolorous, fertile; trama parallel to irregular. Stipe x mm, central, solid to fistulose, cylindrical, sometimes wider at the middle, narrowing towards the base, dark pinkish above annulus (5R 6/4-7/4), purplish below annulus (5R 5/4-6/4), surface sometimes streaked below annulus, bruising dark red-purple (5R 4/4-3/2). Annulus pendant, thin, purple-brown, ephemeral. Flesh white (N9.5), slowly becoming reddish (5R 6/6-6/8) upon cutting or bruising; odour and taste pleasant. Schaffer's cross-reaction negative. Basidia 4-spored, x 8-10 µm, broadly clavate to clavate, with sterigmata 2-5 gm. Basidiospores dark brown in mass, size (7.7 )8.5( 9.3) x (4.9-)5.7(-6.4) µm, elongation (1.1-)1.3(- 1.4) pm, ellipsoid to ovoid, pale brown to dark brown (2.5YR 4/4-5YR 4/4) in water, refractive centre (2 droplets), apiculus lateral, germ-pore not visible. HABITAT: In rings in lawn or pasture, reported amongst Paspalum grass. NEW ZEALAND DISTRIBUTION: Northland, Auckland (Taylor 1983). SPECIMENS EXAMINED: NORTH : Whangarei, near Tanihua Lodge, NZMS 260 Q07/ , PDD

8 Mitchell Agaricus in New Zealand 721 Fig. 2 A, A. cupreobrunneus; B, A. porphyrocephalus. Bars = 5 µm. 4. Agaricus cupreobrunneus (Moll.) Boh. Fig. 2 Pileus mm diam., medium in thickness, convex when young, finally broadly convex to applanate, with copper brown to dark brown (1 0YR 5/6-4/4) scales at centre, decreasing towards margin, pale brown (5YR 6/4-5/6) to reddish (7.5R 5/8-5R 5/10) on bruising; margin inrolled when young, finally inrolled to straight, often with remnants of veil; lamellae insertion free, thin, crowded, pink (5R 9/2) when young, finally dark brown (5YR 3/2); edge concolorous, fertile; trama parallel to irregular. Stipe x 8-15 mm, central, solid to fistulose, cylindrical, narrowing towards the base, white (N9.5) to cream-buff (2.5Y 9/2 to 5Y 9/1) above annulus, surface smooth, brownish (5YR 6/4-5/4) below annulus, surface floccose, browning (5YR 6/ 4-5/4) when bruised. Annulus pendant, broad, brown above, white (N9.5) below, surface streaked. Flesh white (N9.5), pale brown slowly becoming reddish (5R 6/6-6/8) upon cutting or bruising; odour and taste pleasant. Schaffer's cross-reaction negative. Basidia 4-spored, x pm, clavate to broadly clavate, with sterigmata 3-5 pm. Basidiospores brown (5YR 4/4) in mass, size (7.2-)8.3(-9.4) x (4.9-)5.6(-6.3) pm, elongation (1.3-) 1.5 (-1.7) gm, pale brown to brown (2.5 YR 4/4-5YR 4/4) in water, refractive centre (1-2 droplets), apiculus lateral, germ-pore not visible. HABITAT: Gregarious or solitary, often in rings, lawn or pasture. Good edible quality. NEW ZEALAND DISTRIBUTION: Canterbury. SPECIMENS EXAMINED: CANTERBURY: Christchurch, NZMS 260 M36/85 45-, PDD Agaricus bernardii Qua. apud Cke. & Quel. Fig. 3 Pileus mm diam., thick, fleshy, hemispherical when young, finally broadly convexapplanate, ± centrally depressed, surface scaly, scales sometimes become very pronounced during dehydration, whitish (N9.5) when young, finally moderate brown (7.5YR 4/4), bruising reddish to strong reddish orange (7.5R 6/10-5/12); margin thin, inrolled, edge broken with remnants of veil; lamellae insertion free, thin, crowded, pale grey (5YR 8/1-8/2), when young, finally brown to dark brown (5 YR 4/4-3/2); edge pale and sterile; trama parallel to irregular. Stipe x mm, central, solid, cylindrical, base round to narrowing, surface smooth, white (N9.5) above annulus, moderate brown (7.5YR 4/4) below annulus, bruising red to carminered (5R 5/12-3/12). Annulus peronate, sometimes double, thin, white (N9.5) above, moderate brown (7.5YR 4/4) below close to stem, surface smooth. Flesh quickly becoming red to carmine-red (5R 5/ 12-3/12) with cutting or bruising; odour unpleasant, fish-like, taste unpleasant. Schaffer's cross-reaction negative. Basidia 4-spored, x 4-7 p.m, clavate with sterigmata 4-5(-8) pm. Cheilocystidia x 4-8 p.m, broadly clavate to cylindrical, hyaline, abundant. Basidiospores dark brown (5YR 3/2) in mass, size (7.0-)7.9(-8.7) x (5.5-)6.1(-6.7) pm, elongation (1.1-) 1.3(-1.4) pm, spherical to globose, pale brown to brown (2.5 YR 4/4-5YR 4/4) in water, refractive centre (single droplets), apiculus lateral, germ-pore not visible: HABITAT: Gregarious in saline, sandy soils. Can

9 722 New Zealand Journal of Botany, 1999, Vol. 37 Fig. 3 A, A. arvensis; B, A. bernardii; C, A. lanipes; D, A. semotus. Bars = 5 gm. form large (1-10 m diam.) rings in tussock grassland/pasture. Not of high edible quality. NEW ZEALAND DISTRIBUTION: Canterbury. SPECIMENS EXAMINED: : SW of Motukarara Gun Club, near Lake Ellesmere, NZMS 260 M36/75-18-; Ladbrooks, NZMS 260 M36/72-33-; Christchurch, NZMS 260 M3 6/85-45-, PDD Agaricus bisporus var. bisporus (J.Lge) Imb. Fig. 1 Pileus 50-80(-120) mm diam., thick, convex, fleshy, strong brown to brownish orange (5YR 5/4-4/5) scales on white surface (N9.5), bruising reddish (5R 7/6-6/8); margin thick, inrolled when young, finally straight, with remnants of veil; lamellae insertion free, thin, crowded of several lengths, pink (5R 8/4) when young, finally moderate brown (7.5YR 4/4); edge pale and sterile; trama parallel to irregular. Stipe x mm, central, solid to fistulose, cylindrical, base rounded to narrowing, surface smooth, white (N9.5) above annulus, white to brownish below annulus (7.5YR 4/4-5YR 4/4), slight reddening (5R 6/8) on bruising. Annulus peronate, thick and broad, bifurcated edges, white above (N9.5), brown below (7.5YR 4/4-5YR 4/4), white (N9.5) towards the edges, surface smooth. Flesh gradually reddening (5R 7/6-6/8) on cutting or bruising; odour and taste pleasant. Schaffer's cross-reaction negative. Basidia (1-)2(-4)-spored, x 9-11 gm, broadly clavate, with sterigmata 3-5 gm. Cheilocystidia x 7-9 (12) gm, clavate, hyaline, abundant. Basidiospores dark brown in mass, size (6.8-)7.7(-8.5) x (5.6-)6.1(-6.6) gm,

10 Mitchell Agaricus in New Zealand 723 elongation (1.0 )1.3( 1.5) µm, broadly ellipsoid, fawn to pale brown in water, refractive centre (2 droplets), apiculus lateral, germ-pore not visible. HABITAT: Gregarious or in rings in pasture, often in areas with high manure content. Good edible quality. NEW ZEALAND DISTRIBUTION: Canterbury, Otago. Commonly cultivated mushrom. SPECIMENS EXAMINED: CANTERBURY: near Lake Ellesmere, SW of Motukarara Gun Club, NZMS 260 M36/75-18-, growing naturally in saline soils; Ohoka, NZMS 260 M35/72-62-; Lake Pukaki region, NZMS 260 H37/ OTAGO: Taiaroa Head, Otago Peninsular, NZMS 260 J44/33-90-, PDD Agaricus subperonatus (J.Lge) Sing. Fig. 1 Pileus (40-)90(-150) mm diam., very thick, fleshy, hemispherical when young, finally broadly convex to applanate, surface smooth to streaky, reddish brown (10R4/4) to brown (2.5YR 4/6) fibrillose scales, soil particles and humic materials often adhering to surface; margin thick and inrolled, with remnants of white (N9.5) veil; lamellae insertion free, thick, crowded of several lengths, sometimes grown together, pink (5R 9/2-8/4) when young, finally moderate to strong brown (5YR 4/4-3/2), edge pale, sterile; trama parallel to irregular. Stipe x mm, central, solid, cylindrical, swollen sometimes pointed base with mycelial cords, surface fibrillose, white (N9.5) to buff (10YR9/2 lateral,germ- 8/4) above and below annulus. Annulus pendant, white (N9.5) to buff (10YR 9/2-8/4) above and below, surface smooth. Flesh white (N9.5) becoming reddish (7.5R 7/4-6/8) upon cutting or bruising; odour and taste pleasant. Schaffer's cross-reaction negative. Basidia 4-spored, x 6-11 gm, clavate to broadly clavate, with sterigmata 5-6 gm (very hyaline and difficult to see). Cheilocystidia x 7-15 (20) gm, clavate to broadly clavate, hyaline to fawn, abundant. Basidiospores dark brown (5 YR 3/ 2) in mass, size (6.9-)8.4(-9.8) x (5.5-)6.1(-6.7) gm, elongation (1.2 )1.4( 1.6) gm, ellipsoid to subglobose-globose, pale brown to brown (2.5YR 4/ 4-5 YR 4/4) in water, refractive centre (1-3 droplets), apiculus lateral, germ-pore not visible. HABITAT: Gregarious or solitary, with hypogean development. NEW ZEALAND DISTRIBUTION: Canterbury, North Otago (Taylor 1983). SPECIMENS EXAMINED: CANTERBURY: Lincoln, beneath Cupressus macrocarpa, NZMS 260 M36/ , PDD Agaricus bitorquis (Qua.) Sacc. Fig. 2 Pileus (30-)50(-70) mm diam., thick, fleshy, convex when young, finally broadly convex-applanate, surface silky to fibrillose, white (N9.5) when young, bruising orchraceous brown (7.5YR 6/4 4/4), with soil particles often adhering to surface; margin thin, inrolled edge with remnants of veil when young; lamellae insertion free, thin, crowded, pink (5R 8/ 4) when young, finally moderate brown to dark brown (5YR 4/4-3/2), edge pale and sterile; trama parallel to irregular. Stipe x mm, central, solid, cylindrical, to widening at centre, base narrowing, surface smooth to fibrillose, white (N9.5) above annulus, browning below annulus (5 YR 4/4-3/2). Annulus double: lower brownish (5YR 4/4-3/ 2), peronate, prominent; upper white (N9.5), pendant, surface fibrillose, indistinct. Flesh slowly becoming reddish brown (5R5/8-2.5YR5/8) on cutting or on bruising; odour and taste pleasant. Schaffer's cross-reaction negative. Basidia (2-)4-spored, x 5-11.tm, clavate with sterigmata 4-8(-10) gm. Cheilocystidia x 6-11 gm, broadly clavate, hyaline to fawn, abundant. Basidiospores dark brown in mass, size (6.9-)7.4(-7.9) x (5.5-)6.0(-6.4) gm, elongation (1.1 )1.3( 1.4) gm, ellipsoid, pale brown to brown in water, refractive centre (1-2 droplets), apiculus lateral, germ-pore not visible. HABITAT: Gregarious, may be hypogean in lawn or pasture. Good edible quality. NEW ZEALAND DISTRIBUTION: Canterbury. Cultivated at Morton Mushrooms Ltd, Springston, Canterbury. SPECIMENS EXAMINED: NORTH CANTERBURY: Amberley, growing naturally, NZMS 260 M34/87-83-, PDD Agaricus arvensis (J.Schff.) Fr. Fig. 3 Pileus mm diam., thick, campanulate when young, finally convex-applanate, surface silky smooth, white (N9.5) when young, finally yellow (2.5Y 9/8), yellowing intensified by bruising (2.5Y 9/8 to 5Y 8/10); margin thin, inrolled when young, finally straight, with appendiculate remnants of veil; lamellae insertion free, thin, crowded, of several lengths, pale grey when young (5YR 8/2), finally moderate to strong brown (5YR 4/4-3/2); edge pale and sterile; trama parallel to irregular. Stipe

11 724 New Zealand Journal of Botany, 1999, Vol. 37 X mm, central, solid to fistulose, cylindrical, base round, surface smooth, white (N9.5) above annulus and with age becoming amber yellow below annulus (5 Y 8/8), yellowing intensified by bruising (5Y 8/10). Annulus descending, cog-wheel-like, white above with yellowing along the edge, surface silky smooth, white to amber yellow (N9.5 to 5Y 8/ 8) below, surface powdery. Flesh white (N9.5), little effect upon cutting, yellowing upon bruising (5 Y 8/ 8); odour of anise; taste sweet. Schaffer's crossreaction positive. Basidia 4-spored, x 8-10 l.tm, clavate with sterigmata 3-5 pm. Cheilocystidia x 5 10 pm, broadly clavate, hyaline, abundant. Basidiospores strong brown (5 YR 4/4) in mass, size (6.6-)7.1(-7.7) x (5.3-)6.7(-6.1) pm, elongation (1.1-)1.3(-1.4) pm, ellipsoid, dark brown (5YR 3/ 2) in water, refractive centre (1-2 droplets), apiculus lateral, germ-pore not visible. HABITAT: Usually gregarious, sometimes solitary in lawns or pasture, but also found on bare soil under stonefruit trees. NEW ZEALAND DISTRIBUTION: North Otago (Taylor 1983), Canterbury. SPECIMENS EXAMINED: CANTERBURY: Rolleston, NZMS 260 M36/63-35-; Lincoln University, Horticultural Research Area, Block C, NZMS 260 M36/66-29-; Christchurch, Provincial State Highway 74, NZMS 260 M36/85-39-, PDD 68565, Agaricus lanipes (Moll. & J.Schff.) Sing. Fig. 3 Pileus (-250) mm diam., thick, fleshy, convex when young, then convex-applanate, sometimes with a depressed centre, moderate brown (7.5YR 4/4) to dark brown (5YR 3/4-4/6) scales on paler (2.5YR 4/4) surface; margin thin, inrolled, uneven edge, with remnants of veil; lamellae insertion free, thin, crowded, white (N9.5) to pink (5R 8/4) when young, finally dark brown (5YR 3/ 2); edge pale, sterile; trama parallel to irregular. Stipe x mm, central, solid, cylindrical, swollen base, with mycelial cords (bruising yellow 2.5Y 9/8), above annulus white (N9.5) to moderate brown (7.5 YR 4/4), surface fibrillose, with moderate brown (7.5YR 4/4) streaks below annulus, bruising moderate brown (7.5YR 4/4) to yellow (2.5Y 9/8). Annulus pendant, wide, white (N9.5) to moderate brown (7.5YR 4/4) above, moderate brown (7.5YR 4/4) to dark brown (5YR 4/6) below. Flesh white (N9.5), with pinkish (5YR 8/4) to yellow-brown (10YR 8/6) reaction upon cutting or bruising; odour and taste pleasant. Schaffer's cross-reaction negative. Basidia 4-spored, x 8-10 p.m, broadly clavate, with sterigmata 2-4 µm. Cheilocystidia x 7-10 pm, broadly clavate, hyaline to fawn. Basidiospores dark brown (5YR 3/2) in mass, size (7.3-)8.2(-9.1) x (5.2-)5.8(-6.4) µm, elongation (1.4-)1.6(-1.7) pm, strong brown (5YR 4/4) in water, apiculus lateral, germ-pore not visible. HABITAT: Growing through fine bark mulch in cultivated garden area with mature exotic confier species. NEW ZEALAND DISTRIBUTION: Canterbury. SPECIMENS EXAMINED: CANTERBURY: Christchurch, Mona Vale, NZMS 260 M35/78-42-, PDD Agaricus semotus Fr. Fig. 3 Pileus mm diam., thin, convex when young, finally applanate, centre slightly umbonate, with fawn (3.5YR 5.2/4.0) scales on white (N9.5) background at centre, decreasing towards margin, bruising brownish orange (2.5YR 5/7-6/8); margin inrolled when young, fmally straight, edge smooth, with remnants of veil; lamellae insertion free, thin, crowded, of several lengths to alternate, orchraceous salmon (4YR 7.0/7.5) when young, finally umber (7YR 3.7/5.8), edge pale, sterile; trama parallel to irregular. Stipe x 4-10 mm, central, fistulose, cylindrical, club-shaped with swollen sometimes twisted base, smooth to silky, white (N9.5) to umber (7YR 3.7/5.8) above annulus, yellow (2.5Y 9/8) below annulus, especially towards base, bruising yellow (2.5Y 9/8-8/8), base with mycelial cords. Annulus pendant, thin, ± ephemeral, white above, yellow below, surface silky. Flesh white, becoming yellow (2.5Y 9/8-8/8) at stipe base upon cutting or bruising; odour of anise; taste sweet. Schaffer's cross-reaction positive. Basidia 4-spored, x 5-7 p.m, clavate with sterigmata 3-4 pm. Cheilocystidia x 6-8 µm, clavate, abundant, hyaline. Basidiospores dark brown (5YR 3/2) in mass, size (5.7-)6.4(-6.9) x (4.0-)4.5(-4.9) pm, elongation (1.3-) 1.5(-1.7) pm, ellipsoid, pale brown in water (2.5YR 4/4), refractive centre (2-3 droplets), apiculus lateral, germ pore not visible. HABITAT: Gregarious. NEW ZEALAND DISTRIBUTION: SPECIMENS EXAMINED: Northland. NORTH AUCKLAND:

12 Mitchell Agaricus in New Zealand 725 Whangarei, Kamo, Pukenui Walkway, NZMS 260 Q07/23-09-, in humus under Kunzea ericoides, PDD ACKNOWLEDGMENTS We thank the late P. Heinemann, who identified to species the following: A. bisporus, A. bitorquis, A. campestris, A. cupreobrunneus, and A. lanipes; T. Galloway for the illustrations; M. Beisenherz for useful discussion on Agaricus in southern Germany; and P. Horn and R. Close for their encouragement during the early stages of our work in mycology. We thank D. Glenny and two anonymous referees for their critical appraisal of this manuscript; their comments were very helpful and much appreciated. We would especially like to acknowledge the late Marie Taylor for her encouragement and support. Her death is a great loss to both her friends and the scientific community. REFERENCES Bresinsky, A.; Besl, H. 1990: A colour atlas of poisonous fungi. English translation. London, Wolfe Publishing Ltd. 295 p. Chappill, J. A. 1989: Quantitative characters in phylogenetic analysis. Cladistics 5: Cappelli, A. 1984: Agaricus L.: Fr. ss. Karsten (Psalliota Fr.). Italy, M. Candusso. 560 p. Cruickshank, R.; Duguid, J. P.; Swain, R. H. A. 1965: Medical microbiology. A guide to the laboratory diagnosis and control of infection. Edinburgh and London, Livingstone. Gill, M.; Strauch, R. J. 1984: Constituents of Agaricus xanthodermus Genevier: The first naturally endogenous azo compound and toxic phenolic metabolites. Zeitschrift fur Naturforsch. 39c: Heinemann, P. 1974: Quelques Agaricus de Nouvelle- Zelande. Bulletin Jardin Botanique National de Belgique 44: Heinemann, P. 1978: Essai d'une dé de determination des genres Agaricus et Micropsalliota. Sydowia 30: Heinemann, P. 1986: Flore illustrée des champignons d'afrique Centrale. Ministere de l'agriculture - Jardin Botanique National de Belgique 12: Mitchell, A. 1994: Allozyme and basidiospore contributions to phylogenetic analyses of Agaricus species. Unpublished PhD thesis, Lincoln University, Lincoln, New Zealand. Mitchell, A.; Bresinsky, A. 1999: Phylogenetic relationships of Agaricus species based on ITS-2 and 28S ribosomal DNA sequences. Mycologia 91: Mitchell, A.; Walter, M.; Gaunt, R. 1997: Image analysis of Agaricus basidiospores for use in systematics. Biotechnology Techniques 11: Mö11er, F. H. 1950: Danish Psalliota species, I. Friesia IV: Mö11er, F. H. 1952: Danish Psalliota species, II. Friesia IV: Munsell, A. H. 1967: Munsell book of color, neighboring hues edition. Matte finish collection. Baltimore, Munsell Color Company Inc. Pilát, A. 1951: The Bohemian species of the genus Agaricus. Acta Musei Nationalis Pragae VIIB, 1: Ridley, G. S. 1995: The naturalised mushrooms of New Zealand. 2: Agaricus augustus Fries. New Zealand Botanical Society Newsletter 39: 8-9. Schäffer, J.; M611er, F. H. 1938: Beitrag zur Psalliota Forschung. Annales Mycologici 36: Singer, R. 1986: The Agaricales in modem taxonomy. 4th ed. Koenigstein, Koeltz Scientific Books. 981 p. Taylor, M. 1970: Mushrooms and toadstools in New Zealand. Wellington, A. H. and A. W. Reed. 32 p. Taylor, M. 1981: Mushrooms and toadstools in New Zealand. Mobil New Zealand Nature Series. Wellington, A. H. and A. W. Reed. 79 p. Taylor, M. 1983: Some common fungi of Auckland city. Tane 29: Wasser, S. P. 1989: Tribe Agariceae Pat. of the Soviet Union. Koenigstein, Koeltz Scientific Books. 120 p.