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DOI: 10.3852/mycologia.97.4.914
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Mycologia, 97(4), 2005, pp. 914-923.
© 2005 by The Mycological Society of America

Some Xylaria species on termite nests


Jack D. Rogers

     Department of Plant Pathology, Washington State University, Pullman, Washington 99164-6430

Yu-Ming Ju 1

     Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 115, Taiwan

Juergen Lehmann

     Am Duerrbach 19, 97080 Wuerzburg, Germany

   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 TAXONOMY
 KEY TO TAXA
 EXCLUDED OR DOUBTFUL TAXA
 DISCUSSION
 LITERATURE CITED
 

Xylaria arenicola, X. brasiliensis, X. escharoidea, X. furcata, X. nigripes, X. piperiformis and X. rhizomorpha represent ancient names of fungi known to inhabit abandoned termite nests. We attempt to redescribe them and to reduce the confusion among them. Xylaria tanganyikaensis and X. readeri, species that might be associated with termite nests, are described. We describe a new variety, X. furcata var. hirsuta, and discuss an unnamed fungus that probably represents a new species. Photographs and a key are presented to aid the identification of these taxa.

Key words: systematics, Xylaria arenicola, Xylaria brasiliensis, Xylaria escharoidea, Xylaria furcata, Xylaria furcata var. hirsuta, Xylaria nigripes, Xylaria piperiformis, Xylaria readeri, Xylaria rhizomorpha, Xylaria tanganyikaensis, Xylariaceae


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 TAXONOMY
 KEY TO TAXA
 EXCLUDED OR DOUBTFUL TAXA
 DISCUSSION
 LITERATURE CITED
 
The Xylaria species that fruit on inactive or abandoned insect nests have long intrigued mycologists. A major obstacle to meaningful discussions and correlations of observations and data has been the generally inaccurate identifications of the more common taxa. A major factor leading to inaccurate identifications has been the failure to observe a significant morphological feature of the ascospore—the germination site. Boedijn (1959)Go erected the new genus Pseudoxylaria Boedijn on Sphaeria (Cordyceps) nigripes Klotzsch ({equiv} Xylaria nigripes [Klotzsch] Sacc.) based in part on the supposition that the ascospores lack a germination site. He erected family Sarcostromellaceae to include Pseudoxylaria and Sarcostromella, the latter now generally considered a synonym of Camarops P. Karst. in the family Boliniaceae (Nannfeldt 1972Go). Dennis (1961)Go considered Pseudoxylaria (Boedijn) Dennis to be a subgenus of Xylosphaera Dumortier nom. rej. (= Xylaria Hill ex Schrank), based on the horny texture and dark interior of the stroma and the ascospores apparently devoid of a germination site. He added Xylosphaera tanganyikaensis Dennis and Xylosphaera furcata (Fr.) Dennis to the subgenus (Dennis 1961Go). Of note, all these taxa have germination slits in the ascospores and, although those of X. nigripes and X. furcata are small, they are easily seen with an oil immersion lens. Another result of the failure to observe ascospore germination sites was the confusion of taxa with germination slits with some other taxa with germination pores. Both Petch (1906Go, 1913)Go and von Höhnel (1908)Go made extensive collections of Xylaria spp. on termite nests and provided interesting observations on their biology, but their failures to delineate the taxa involved have diminished somewhat the value of their observations. Sands (1969)Go summarized observations of Xylaria on termite nests, considering them to be saprophytes. Heim (1977)Go summarized data on fungi associated with termites, among them the Xylaria spp. associated with nests. He considered them to be saprophytes; his summary of the taxa involved added little to the elucidation of specific taxa encountered. Batra and Batra (1979)Go studied the interactions of Odontotermes obesus with Xylaria species and the mushroom genus Termitomyces. Both these fungi are associated in termite nests and were considered to be mutualistic symbionts. Batra and Batra (1979)Go followed Heim (1977)Go and others in identifying the Xylaria. Two of us ( J.D.R. and Y.-M.J.) have been interested in Xylaria for many years. The other of us ( J.L.) has studied termite nests more than 20 years; his aim has been to clarify the relationship of coexisting mycelia of Xylaria spp. and certain mushrooms in the nests of fungus-cultivating termites. The termite nests studied by J.L. were of Macrotermitinae of which there are estimated 300 species out of a total of at least 2000 termite species. J.L. furnished J.D.R. with numerous Xylaria collections from termite nests and these, along with data from other sources, form the basis of this attempt to sort out some of the taxa associated with termite nests.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
TAXONOMY
 KEY TO TAXA
 EXCLUDED OR DOUBTFUL TAXA
 DISCUSSION
 LITERATURE CITED
 
Asci, ascospores, conidiogenous cells and conidia were examined by differential interference microscopy (DIC) and bright field microscopy (BF). Material was mounted in water and Melzer’s iodine reagent for examination by DIC and BF. The numbers of ascospores, conidia, perithecia, asci and conidiophores that were measured to form the size ranges in the descriptions are 20, 10, 5, 5, and 5, respectively. The stromatal size ranges were based on all available stromata in the cited specimens. The color designations are from Rayner (1970)Go. We have attempted to obtain cultures from the collections made by one of us ( J.L.) but unfortunately failed.


   TAXONOMY
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 TAXONOMY
KEY TO TAXA
 EXCLUDED OR DOUBTFUL TAXA
 DISCUSSION
 LITERATURE CITED
 
Taxa that are known to be associated with termite nests.— – Xylaria nigripes (Klotzsch) M. C. Cooke, Grevillea 11: 89. 1883. FIGS. 1–4Go



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  		FIGS. 1–27. Xylaria species. 1–4. X. nigripes (from neotype). 1. Stroma. 2. Stromatal surface. 3. ascus apical rings. 4. Ascospores. 5–10. X. escharoidea (5–8 from holotype of X. eschroidea, 9, 10 from syntype (K[M] 125998) of X. gardneri). 5, 9. Stromata. 6, 10. Stromatal surface. 7. Ascus apical rings. 8. Ascospores. 11–14. X. furcata (from neotype). 11. Stromata. 12. Stromatal surface. 13. Ascus apical rings. 14. Ascospores. 15–18. X. furcata var. hirsuta (from holotype). 15. Stroma. 16. Stromatal surface. 17. Ascus apical rings and ascospores. 18. Ascospores. 19–22. X. piperiformis (from holotype). 19. Stromata. 20. Stromatal surface. 21. Ascus apical rings and ascospore. 22. Ascospores. 23–27. X. sp. "white surface." 23. Stromata. 24, 25. Stromatal surfaces. 26. Ascus apical rings. 27. Ascospores. FIGS. 3, 5, 7, 8, 13, 14, 17, 18, 21, 22, 26, 27 by DIC. Bars in FIGS. 1, 9 = 1 cm; 2, 6, 10, 20, 25 = 0.25 mm; 3, 4, 7, 8, 13, 14, 17, 18, 21, 22, 26, 27 = 2.5 µm, 5, 11, 15, 19, 23 = 5 mm; 12 = 0.5 mm; 16, 24 = 1 mm.

 
[{equiv} Sphaeria (Cordyceps) nigripes Klotzsch, Linnaea 7:203. 1832.

{equiv} Xylosphaera nigripes (Klotzsch) Dennis, Kew Bull. 13: 105. 1958.

{equiv} Pseudoxylaria nigripes (Klotzsch) Boedijn, Persoonia: 18. 1959.]

Stromata with more or less cylindrical fertile head from an abrupt long rooting stipe, up to at least 15 cm long x 2–5 mm thick, the head 3–6 cm long, with apex rounded or abruptly acute, at first dull yellowish, becoming grayish, then dull black, the central core blackish. Very hard and horny when mature, softening when wet. Surface smooth or longitudinally wrinkled. Perithecia more or less embedded, 0.1–0.3 mm diam, closely arranged. Ostioles more or less papillate. Asci long-stipitate, 65–75 x 3–4 µm, the spore-bearing part ca. 30 µm, with apical ring minute, bluing in Melzer’s iodine reagent. Ascospores brown, ellipsoid-inequilateral, somewhat flattened, smooth, (3.5–)4.5–5(–6) x 2–3 µm, with germ slit full-length on concave side.

Neotypification.. An attempt to locate authentic material to typify X. nigripes failed. As will be seen later herein, this species has been confused so often with others that early illustrations and other potential materials are not especially useful. We thus neotypify X. nigripes on this material: INDONESIA. NORTH SULAWESI: Dumoga-Bone National Park, at confluence of Toraut and Tumpah Rivers, vicinity Project Wallace Base Camp, 0°34'N, 123°57'E, elevation 211 m, on ground, Sep 1985, Samuels, G.J. 2031 (NEOTYPE WSP 71140, ISONEOTYPES BO, NY).

Specimens examined.. INDONESIA. JAVA: Buitenzorg Botanical Garden, 1907–08, leg. von Höhnel, Rehm: Ascomycetes 1810 (FH) (it is noteworthy that other collections under No. 1810 in FH and S are X. escharoidea); NORTH SULAWESI: Dumoga-Bone National Park, confluence of Toraut and Tumpah Rivers,? on termite nests, Sep 1985, Samuels, G.J. 1972 ( JDR, NY). SRI LANKA (formerly CEYLON). Peradeniya, Jan 1910, Petch, T. 3029 (K).

Commentary.. The above description is essentially like those of Boedijn (1959)Go and Dennis (1961)Go. Boedijn (1959)Go observed that young stromata before perithecial formation bear conidiophores up to 25 µm long x 1.5–2 µm wide bearing hyaline conidia 2.5–5 x 1.5–2 µm. Petch (1913)Go stated that certain stromata bear conidia before perithecial production, but others seem to bear only conidia or only perithecia, respectively. Petch, however, mixed observations on several Xylaria species and his conclusions must be viewed in this light. Von Höhnel (1908)Go grew what he believed to be X. nigripes on termite nest fragments under bell jars and produced photographs of the fungus (Taf. 1 and 2). Examination of many von Höhnel collections housed in herbaria FH and S indicate strongly that his observations and photographs represent, in fact, X. escharoidea (see later herein).

The following specimens have been labeled as X. nigripes but have been misidentified or do not fit our concept of this species owing to ascospore size and/or stromatal characteristics: DEMOCRATIC REPUBLIC OF CONGO. DISTRICT DES LACS ÉDOUARD ET KIVU: Panzi Kivu, altitude 1650 m,? on termite nests, Jan 1954, Goosens-Fontana, M. 5358 (K), one of the collections cited by Dennis (1961)Go, with ascospores 5.5–6 x 2.5–4 µm (Dennis gives the ascospore range of Xylaria (as Xylosphaera) nigripes as 4–5 x 3.5 µm). GHANA. Cape Coast, near Ghana National College, sine anno, Rose, A. C. 7316A, as X. nigripes "obese form" by Dennis, R.W.G. (K), more robust than usually encountered and ascospores a bit larger than usual for the species, 5–6.5 x 2.5–4 µm. INDIA. Pusa, on soil, 20 Jul 1906, Butler, Herb. Crypt. Ind. Orient. 1172 (S), ascospores averaging larger, 6–7.3 x 3.7 µm; same data as above, 26 Jul 1906, Butler, Herb. Crypt. Ind. Orient. 1171 (S), ascospores as previous specimen. INDONESIA. JAVA: on white ant nests, Feb 1922, van Overeem 673 (K), possibly representing X. nigripes, but ascospores averaging a bit larger, 5–7 x 3–3.5 µm. MALAYSIA. MALAYA: sine anno, Ridley, W.N., det. Petrak (K), stroma fragmentary and ascospores rather large, 8 x 4–4.5 µm. PHILIPPINES. LAGUNA PROV.: Luzon, Los Bãnos, Mount Maquiling, Sep 1917, Baker, C. F., det. Petrak (K), typical X. escharoidea. SRI LANKA (formerly CEYLON). Peradeniya, Jun 1913, Petch, T. 3483 (K), typical X. escharoidea. UGANDA. on old termite combs, Sep 1937, Hansford, C.G. 2283 (K), typical X. escharoidea; on open soil near forest edge, sine anno, Lyle K. A. M72 (K), stroma clavate-flattened rather than cylindrical and ascospores large, 8–9 x 5 µm.

Xylaria escharoidea (Berk,) Fr., Nov. Acta Reg. Soc. Sci. Upsal., ser. 3, 1:128. 1851. FIGS. 5–10Go

[{equiv} Sphaeria escharoidea Berk., Ann. Mag. Nat. Hist. 10: 385. 1843.

= Xylaria gardneri (Berk.) Berk., J. Linn. Soc. Bot. 14: 118. 1873

{equiv} Sphaeria gardneri Berk., London J. Bot. 6:513. 1847.

= Xylaria melanaxis Ces., Atti Accad. Sci. Fis. 8:16. 1879.

= Xylaria glaucescens Sacc., R. Accad. Pad., p 189. 1917.]

Stromata cylindric-fusoid, with short to long above-ground stipe, (2–)8–14 cm high x (2.5–)4–5 mm diam, with long rooting stipe, at first white to yellowish with black ostioles, then dull black as outer layer sheds; internally black at core but pale around perithecia. Texture hard. Surface roughened with close-set ostioles and longitudinal wrinkles but more or less devoid of wrinkles when fresh. Perithecia 0.15–0.2 (–0.5) mm diam. Ostioles papillate. Asci eight-spored, cylindrical, long-stipitate, ca. 50 µm total length x 3–4.4 µm broad, the spore-bearing part 22–32 µm long, with apical ring bluing in Melzer’s iodine reagent, wedge-shaped, minute. Ascospores brown, ellipsoid-inequilateral, flattened, smooth, 3.5–4.5(–5) x (1.5–)2 x 2.5–3(–3.5) µm, with median germ pore on narrow concave side. Paraphyses abundant.

Cultural characteristics and anamorph have been described by Ju and Rogers (1999)Go.

Specimens examined.. AFRICA (southwest). 1913, Thompson, W.P. (FH). ERITREA. Ghinda, Dongollo, between rocks of wall, 6 Feb 1916 (PAD HOLOTYPE of X. glaucescens). INDIA. Pusa, on ground, 26 Jul 1906, Butler, E., Herb. Crypt. Ind. Orient. 1164, as X. nigripes (S); Pusa, on ground, 25 Jul 1906, Butler, E., Herb. Crypt. Ind. Orient. 1170, as X. nigripes (S); Dehra Dun, on stony ground, 2 Aug 1905, Rao, K.N., Herb. Crypt. Ind. Orient. 1173, as X. nigripes (S); Dehra Dun, from nest No. 23 of Odontotermes microdentatus, 8 Aug 1989, Lehmann, J. 1305 (5–5) & 1306 (5–7) (WSP 71146); Dhulia, on cultivated soil, 30 Sep 1909, Kulkarni, G., Herb Crypt. Ind. Orient. 1168, as X. nigripes (S); Pusa, on ground, 26 Jul 1906, Butler, E., Herb. Crypt. Ind. Orient. 1166, as X. nigripes (S); Jullundur, 8 Sep 1907, Dobbs, A.C., Herb. Crypt. Ind. Orient. 1163, as X. nigripes (S). INDONESIA. JAVA: Buitenzorg Bot. Garden, 1907–1908, von Höhnel, Rehm: Ascomycetes 1810, as X. nigripes (S), all von Höhnel specimens labeled as X. nigripes under No. 4371 in (FH) being X. escharoidea; NORTH SULAWESI: Dumoga-Bone National Park, vicinity Hog’s Back Camp, on ground, 30, 31 Oct 1985, Samuels, G.J. (BO, JDR, NY). MALAYSIA. BORNEO: Sarawak, Beccari, O., Crittogame di Borneo 217 (RO HOLOTYPE of X. melanaxis). PHILIPPINES. LAGUNA PROV.: Luzon, Mount Maquiling, auf einem Baumstamm, Sep 1917, Baker, C0 F., Reliquiae Petrakianae (Graz) 2298, as X. nigripes (S). SRI LANKA (formerly CEYLON). Apr 1843, König (K[M] 125994 HOLOTYPE of X. escharoidea); Nov 1867 (K[M] 125998 SYNTYPE of X. gardneri); Peradeniya, Jun 1913, Petch, T. 3483, as X. nigripes (K); sine anno, Petch, T., Petrak, F. 1881, as X. nigripes (GZU). THAILAND. Sukhothai, Historical Park, near termite nest, 20 Jul 1994, Bandoni, R.J. & Flegel, T.W. 10644 ( JDR); Phetcha-boon, Nam Nao, near headquarters, on old termite nest, 20 Jul 1996, Bandoni, R.J. & A.A. & Flegel, T.W. 12125 ( JDR); Kanak, Sakaerat Station, on termite nest, 18 Jun 1996, Bandoni, R.J. & A.A. & Flegel, T.W. 11737 ( JDR); Nakorn Nayok, Khao Yai Park, Haew Suat Trail, on wood, 18 Oct 1994, Bandoni, R.J. & Flegel, T.W. 11026 ( JDR). UGANDA. on old termite combs, Sep 1937, Hansford, C. G. 2283, as X. nigripes (K).

Commentary.. Xylaria escharoidea seems common on termite nests throughout Asia and elsewhere. It has been widely misinterpreted as the much less common X. nigripes. Dennis (1961)Go considered X. escharoidea and X. gardneri to be synonyms of X. nigripes, despite the difference in the shape of the ascospore germination sites of the former taxa and the latter. As stated earlier, he apparently did not observe germination sites. This fungus has been widely accepted as X. melanaxis Ces. in recent years. It is unfortunate that this highly descriptive name must become a synonym to the nondescript, but earlier, X. escharoidea.

Neither von Höhnel (1908)Go nor Petch (1906Go, 1913)Go discriminated among collections of X. nigripes and X. escharoidea, usually considering every collection to be the former. The relationship of X. escharoidea with X. micrura Speg. is unknown.

Xylaria furcata Fr., Nova Acta Regiae Soc. Sci. Upsal., ser. III, 1:128. 1851. FIGS. 11–14Go

[{equiv} Sphaeria (Cordyceps) dichotoma Lév., Ann. Sci. Nat. Bot., sér. III, 3:45. 1845; non Xylaria dichotoma (Mont.) Fr., 1851.

{equiv} Xylosphaera furcata (Fr.) Dennis, Bull. Jardin Botan. État Brux. 31:116. 1961.

= Xylaria scoparia Pat., J. Bot. (Morot) 5:318. 1891.]

Stromata usually highly branched, with or without an obvious main rachis, with branches terete or flattened, 1–5 mm diam, the whole up to 7 cm high. Color at first yellowish with black ostioles, later becoming brown, at last dull black. Interior at first yellowish, becoming brown and finally black at center. Texture at first soft, becoming horny and hard. Surface smooth except for perithecial elevations, ostioles, and wrinkles, glabrous or finely pubescent. Perithecia 0.1–0.2(–0.3) mm diam, crowded, with contours highly conspicuous or less frequently immersed. Ostioles papillate. Asci 8-spored, short-stipitate, 29–37 µm total length x 3.7 µm wide, the spore-bearing part 26–34 µm long, with apical ring bluing in Melzer’s iodine reagent, wedge-shaped, minute. Ascospores brown, ellipsoid-inequilateral, somewhat flattened, smooth, 3.5–4.5(–5.5) x 2 x 2.5–3 µm, with long germ slit on narrow concave side. Paraphyses abundant.

Neotypification.. No type material has been discovered. Thus we provide a neotype from the abundant material collected by von Höhnel in Buitenzorg, Java. Many packets of his material are in herbaria FH and S and probably represent the same species. Von Höhnel provided excellent photographs of X. furcata (von Höhnel 1908Go, Taf. 3 & 4). Rehm produced exsiccati from von Höhnel’s material under Rehm: Ascomycetes 1812. INDONESIA. JAVA: Buitenzorg, on termite nests, 1907–08, von Höhnel A4371 (FH NEOTYPE), numerous packets of von Höhnel material are deposited under this number and date. The particular neotype specimen is clearly marked.

Specimens examined.. INDIA. Dehra Dun, from nest 23 of Odontotermes microdentatus, 8 Aug 1989, Lehmann, J. 214 (16–1), 215 (16–2), 216 (16–3), 217 (16–4), 218 (16–5), 219 (16–6), 1285 (16–7), 1287 (16–9), 1289 (16–11), 1290 (16–12), 1291 (16–13), 1292 (16–14), 1300 (16–15), 1299 (16–16), 1298 (16–17), 1301 (16–19), 1304 (16–20), 1302 (16–21) & 1303 (16–22) (WSP 71144). INDONESIA. JAVA: from termite nests, sine anno,? von Höhnel (S); JAVA: from termite nests, 1908, von Höhnel (S); JAVA: Buitenzorg Botanical Garden, on soil over termite nests, 1908, von Höhnel, Rehm: Ascomycetes 1812 (S); JAVA: on termite nests, 1907–08, ex herb. von Höhnel (K). SRI LANKA (formerly CEYLON). Peradeniya, Dec 1909, Petch, T. (K). VIETNAM. Tonkin, Bon (FH LECTOTYPE [selected here] of X. scoparia); Tonkin, Ha Noi, 1890, Bon 4399 (FH SYNTYPE of X. scoparia), immature; Tonkin, Ke’so,’ 1890, Bon 4470 (FH SYNTYPE of X. scoparia), immature. Other collections that might represent X. furcata, but with somewhat larger ascospores (4.4–5.9 x 2.9 x 3.7 µm): CHINA. HAINAN: Tingan, on soil, Sep 1934, Deng, S.Q. 4219 (BPI 584607); Nan-king, Ling-Ku-Sze Woods, on soil, sine anno, Teng, S.C. 2743 (BPI 584601).

Commentary.. As we understand this name X. furcata, it was given by Fries (1851)Go as a new name for Sphaeria dichotoma Lév. non Montagne. Xylaria furcata was mentioned by Fries only in the protologue of X. tricolor Fr. Material of X. tricolor at UPS is sterile. No Fries material of X. furcata, Sphaeria dichotoma, or Cordyceps dichotoma exists in UPS, according to Svengunnar Ryman (pers comm). The herbarium of J.H. Léveillé was destroyed in 1870–1871. Some of Léveillé’s collections are extant in E, but a search kindly made by Roy Watling did not reveal material relevant to this study. Dennis (1961)Go interpreted X. furcata from Africa as a branched hirsute stroma bearing superficial perithecia with ascospores 4–5 x 2 µm, stating that his interpretation of the species was that of Petch. It would have been useful if Dennis had cited the particular Petch specimen on which he based his concept. Specimens of X. furcata from Petch that we have examined are not hairy and have much smaller perithecia than the specimen that Dennis (1961)Go cited from Congo, Louis 14866. We believe that the Congo material represents an undescribed taxon that is described later herein. In any case no type material of X. furcata is known to exist. It thus is neotypified herein.

There has been considerable confusion about X. furcata and its conidial state. Petch (1906Go, 1913)Go was uncertain if X. furcata and X. nigripes were, in fact, morphs of the same species. Dixon (1965)Go described a conidial state for X. furcata (as Xylosphaera furcata), named Padixonia bispora Subram. (Subramanian 1972Go). Dixon (1985)Go came to believe that P. bispora is the conidial state of an undescribed Xylaria rather than of X. furcata. At present we consider the conidial state of X. furcata to be unknown.

The relationship between X. furcata and X. nigripes is unknown. Ascospores of these species are similar. Xylaria furcata has highly branched stromata and long tapering acute apices, as well as highly evident perithecial elevations in most collections. Xylaria nigripes is a more stately fungus, usually sparingly branched without conspicuous perithecial elevations. Culture-based and molecular studies probably would clarify the relationship. In any case, X. nigripes seems to be uncommon or even rare compared to X. furcata and X. escharoidea.

There is little doubt that X. scoparia is conspecific with X. furcata despite the fact that the former was reported to be collected from rotten wood in Vietnam. Dennis (1956)Go suspected that X. scoparia is the corresponding species of X. rhizomorpha in the eastern tropics.

Xylaria furcata Fr. var. hirsuta J.D. Rogers & Y.-M. Ju, var. nov. FIGS. 15–18Go

[Xylosphaera furcata (Fr.) Dennis sensu Dennis (1961)Go.] A Xylaria furcata var. furcata differt in stromatibus hirsuta.

Differs from the typical variety of Xylaria furcata in the hirsute stroma.

Dennis (1961)Go considered this to be typical Xylaria furcata. It does not agree, however, with the more or less glabrous material that is common in Asia. The material examined likewise apparently is not black at the core or at least had not blackened. We consider it to be a variety at present, but additional collections might convince us that it is a distinct species.

Specimen examined.. DEMOCRATIC REPUBLIC OF CONGO. YANGAMBI: Isalowe, altitude 470 m, on soil, May 1939, Louis, F. 14866, as X. furcata by Dennis, R.W.G. (K[M] 125997 HOLOTYPE).

Xylaria piperiformis Berk., Hooker’s J. Bot. 6:225. 1854. FIGS. 19–22Go

[= Xylaria mutabilis Curr., Trans. Linn. Soc. London, ser. II. Bot., 1:129. 1876.]

Stromata fusiform to long cylindrical with acute tapered apices, with short or long, glabrous stipes, unbranched or branched from the base, solitary to caespitose, 1–8 cm high x 1–2.5 mm thick. Extus Sienna (8) to Dark Brick (60), becoming blackish; white internally. Surface roughened by close set perithecial elevations. Texture soft. Perithecia globose to obovate, 0.2–0.3 mm diam x 0.3 mm high, with distinct contours. Ostioles papillate. Asci 8-spored, stipitate, ca. 44 µm total length x 4.4 µm broad, with spore-bearing part ca. 36 µm long, with ascus apical ring bluing in Melzer’s iodine reagent, cuboid, 1.5 µm. Ascospores brown to dark brown, ellipsoid-inequilateral to somewhat triangular, flattened, smooth, (5–) 5.5–7 x 3 x 3.5–4(–4.5) µm, with a full-length slit on flattened narrow side.

Specimens examined.. INDIA. WEST BENGAL: Sikkim (K[M] 125999 HOLOTYPE of X. piperiformis); Calcutta, Botanic Garden, on brick-laid paths, Jul 1867, Kurz, S. 1790 (K[M] 125996 HOLOTYPE of X. mutabilis). Northern India, from nest No. 16 Odontotermes microdentatus, 26 Sep 1998, Lehmann, J. 950 (9-2), 968 (9-3) & 936 (9-4) (WSP 71142). Dehra Dun, from nest No. 6 of Odontotermes microdentatus, 26 Sep 1988, Lehmann, J. 1103 (10-d) (WSP 71141); Dehra Dun, from nests of Odontotermes distans, 18 Sept 1986, Lehmann, J. 505 (24-1), 1337 (24-2), 1350 (24-3), 1346 (24-4), 1332 (24-5), 1358 (24-6), 1349 (24-7) & 1353 (24-8) (WSP 71143).

Commentary.. Xylaria piperiformis is an easily recognizable fungus by its color and stately sparingly branched habit. It was listed by Dennis (1961)Go as a synonym of X. nigripes from which it differs in having prominent perithecial contours on the stromatal surface, whitish stromatal interior instead of a blackish central core, and larger ascospores. This fungus is known mostly from India. San Martín (1992)Go reported X. cf. piperiformis from Mexico, which likely belongs here.

Xylaria sp. "white surface" FIGS. 23–27Go

Stroma ca. 2 cm high, highly branched, 4 mm at base with branches 1–2 mm diam, white with black perithecial ostioles, probably black at maturity, white inside possibly black at maturity. Fairly soft. Surface rough from ostioles and perithecial contours. Perithecia 0.1–0.2 mm diam, the contours very distinct. Ostioles sharply papillate. Asci 8-spored, stipitate, ca. 44 µm total length x 4.4 µm wide, with spore-bearing part ca. 36 µm, with ascus apical ring bluing in Melzer’s iodine reagent, cylindrical, 0.7–1.5 µm high, 0.7–1.5 µm wide. Ascospores light brown, ellipsoid-inequilateral, flattened, smooth, 5–6 x 3 x 4 µm, with slit on flattened narrow side.

Specimens examined.. INDIA. Northern India, Dehra Dun, from nest No. 2 of Odontotermes obesus, 1988, Lehmann, J. 1268, 1269, 1270, 1273, 1274, 1275, 1276, 1277, 1278, 1279, 1280, 1281, 1282 & 1283 (WSP 71145).

Commentary.. This fungus resembles X. furcata as defined earlier herein, but the ascospores average larger and the surface is whiter. Von Höhnel (1908)Go mentioned such a fungus and apparently believed it to be a form of X. furcata. We were tempted to describe it as new, but the only mature material was from a fragmentary stroma. We provide here photographs of this fungus.

Species that are likely associated with termite nests.— – Some noticeable Xylaria species are reported to have a connection with termite nests or, at least, to grow out from soil. Nonetheless they rarely have been collected and are represented only by one single specimen or a few. Their connections with termite nests thus remain to be reconfirmed.

Xylaria arenicola Welw. & Currey, Trans. Linn. Soc. 26:280. 1868. FIGS. 28–31Go



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  		FIGS. 28–45. Xylaria species. 28–31. X. arenicola (from holotype). 28. Stromata. 29. Stromatal surface. 30. Ascus apical rings. 31. Ascospores. 32–36. X. brasiliensis (from lectotype). 32. Stromata. 33. Stromatal surface. 34. Ascus apical ring and ascospores. 35. Ascospore surrounded by a gelatinous sheath. 36. Ascospores. 37, 38. X. readeri (from type, S). 37. Ascospores. 38. Ascospores surrounded by a gelatinous sheath. 39–41. X. rhizomorpha (isotype, S). 39. Stroma. 40. Stromatal surface. 41. Ascospores. 42–45. X. tanganyikaensis (holotype). 42. Stromata. 43. Stromatal surface. 44. Ascus apica rings and ascospore. 45. Ascospores. FIGS. 30, 31, 34–38, 41, 44, 45 by DIC. Bars in FIGS. 28, 32, 42 = 5 mm; 29, 33, 40, 43 = 0.25 mm; 30, 31, 34–38, 41 = 2.5 µm; 39 = 1 cm; 44, 45 = 10 µm.

 
[{equiv} Xylosphaera nigripes (Klotzsch) Dennis var. arenicola (Welw. & Currey) Dennis, Bull Jardin Botan. État Brux. 31:116. 1961.

{equiv} Xylaria nigripes (Klotzsch) Cooke var. arenicola (Welw. & Currey) Hawksw., Trans. Brit. Mycol. Soc. 61:200. 1973.]

This fungus resembles X. nigripes from which it differs mainly in having larger ascospores, 5.5–7(–7.5) x 3–3.5 µm. If Dennis’ concept is accepted, some collections that resemble X. nigripes, but with larger ascospores, could be accommodated here.

Specimen examined.. ANGOLA. between Cazella and Pungo Audongo, on soil, Jan 1857, Welwitsch, E., Iter Angolense 92 (K[M] 125992 HOLOTYPE).

Xylaria brasiliensis (Theiss.) C. G. Lloyd, Mycol. Writings 1919. FIGS. 32–36Go

[{equiv} Xylaria arenicola Welw. & Curr. var. brasiliensis Theiss., Ann. Mycol. 6:343. 1908.

{equiv} Xylaria scotica Cooke var. brasiliensis (Theiss.) Theiss., Xylariaceae Austrobrasilienses 1:5. 1909.]

The stromatal features of the type material from S (BRAZIL. ad nidos termitidum, Theissen, F. 28 [S LECTOTYPE]) resemble those of X. piperiformis, but X. brasiliensis has slightly longer, more light-colored, less curved ascospores, 7–8 x 3.5–4 µm, which are enclosed in a gelatinous sheath and have a less than to slightly less than spore-length germ slit. The perithecia are larger in diameter 0.3–0.4 mm.

Xylaria readeri F. Muell., Grevillea 22:17. 1893. FIGS. 37, 38Go

This fungus was reported from sandy soil (AUSTRALIA. VICTORIA: Wimmera Desert, on roots of herbaceous plants in sand, 1893, Reader, F. [K, S TYPES]). The types are as follows: Stromata up to ca. 15 cm, composed of a long "root" and stipe with a fertile head 3–5 mm long x 2–3 mm wide, blackish. Perithecia rounded, ca. 0.3 mm diam. Ostioles slightly papillate. Intact asci not seen. Ascus apical ring bluing in Melzer’s iodine reagent, cuneate, minute. Ascospores dark brown, ellipsoid, smooth, (7–)8–9.5 x 3–4 µm, with a less than spore-length germ slit, surrounded by a gelatinous sheath.

It is possible that this fungus was associated with insects, but proof is lacking. Of interest, Saccardo (1899)Go gives the ascospores as 14–15 x 5–6 µm whereas Lloyd (1924)Go gives the ascospores as 8 x 4 µm and presents an excellent photograph of the fungus. Until there is proof of actual association with insects and until the discrepancies in ascospore size are clarified the status of this fungus is in question.

Xylaria rhizomorpha (Mont.) Mont., Ann. Sci. Nat. Bot., sér. IV, 3:107. 1855. FIGS. 39–41Go

[{equiv} Hypoxylon rhizomorpha Mont., Ann. Sci. Nat. Bot., sér. II, 13:341. 1840.]

Xylaria rhizomorpha is probably known only from type material. Dennis (1956)Go examined the holotype at PC. The part of the type that we studied is from S (GUYANA. May 1836, Leprieur, C. 234 [S ISOTYPE]) and is composed of one stroma only. This fungus and X. furcata have similar ascospore morphologies. It is also like X. furcata in having naked perithecia. However the perithecia of X. rhizomorpha, 0.4–0.5 mm diam, are much larger than those of X. furcata. Cesati (1879)Go listed the name from Borneo, but, according to Lloyd (1924)Go, Cesati’s material is not a Xylaria species at all.

Xylaria tanganyikaensis (Dennis) Hawksw., Trans. Br. Mycol. Soc. 61:200. 1973. FIGS. 42–45Go

[{equiv} Xylosphaera tanganyikaensis Dennis, Bull. Jardin Botan. État Brux. 31:116. 1961.]

This fungus might or might not be associated with termite nests. It is included here because Dennis (1961)Go included it in subgenus Pseudoxylaria. This was a curious disposition of this fungus, which has large ascospores with prominent germination slits and white stromatal interior. These are not features that Boedijn (1959)Go or Dennis (1961)Go employed to define this assemblage of Xylaria. This fungus is known only from the type material (DEMOCRATIC REPUBLIC OF CONGO. TANGANYIKA TERRITORY: Lake Tanganyika, Edith Bay, Cap Kibwesa, buried in sand, 14 Feb 1947, Van Meel, L. 907 [HOLOTYPE BR, ISOTYPE K]), upon which the following description is based. Fertile part flattened, mitten-shaped, with long cylindrical rooting part, up to 12 cm total length x 0.8–1 cm wide, the surface whitish to grayish, finely cracked, with black ostioles, the root brownish, tomentose; interior white. Intact asci not observed. Ascus apical ring bluing in Melzer’s iodine reagent, slightly funnel-shaped, 2–3 µm high x 4–4.5 µm broad. Ascospores blackish brown, ellipsoidal to more or less rectangular to irregular, smooth, (13.5–)15–17(–19) x 7.5–9 µm, with full-length germ slit straight to undulating.


   KEY TO TAXA
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 TAXONOMY
 KEY TO TAXA
EXCLUDED OR DOUBTFUL TAXA
 DISCUSSION
 LITERATURE CITED
 

1. Ascospores with median germ pore on narrow concave side, 3.5–4.5(–5) x (1.5–)2 x 2.5–3(–3.5) µm X. escharoidea
1. Ascospores with germination slit on concave side 2
    2. Stromata usually highly branched, with prominent perithecial mounds 3
    2. Stromata usually sparingly branched, and, if branched, usually from near rooting base, with entirely buried perithecia 6
3. Perithecia 0.4–0.5 mm diam. Ascospores 4.5–5 x 2–2.5 µm X. rhizomorpha
3. Perithecia 0.1–0.3 mm diam 4
    4. Stromata with white pulverulent surface, becoming blackish at maturity. Ascospores 5–6 x 3 x 4 µm X. sp. "white surface"
    4. Stromata dull white when immature, becoming blackish at maturity. Ascospores 3.5–4.5(–5.5) x 2x 2.5–3 µm 5
5. Stromatal surface glabrous X. furcata
5. Stromatal surface conspicuously hairy X. furcata var. hirsuta
    6. Stroma flattened, mitten-shaped (in type), with ascospores (13.5–)15–17(–19) x 7.5–9 µm. X. tanganyikaensis
    6. Ascospores not exceeding 10 µm in length 7
7. Stromata usually more robust, more or less cylindrical, often exceeding 10 cm total length and 3 mm diam 8
7. Stromata usually slender, fusiform to cylindrical, infrequently exceeding 10 cm total length and 3 mm diam 9
    8. Ascospores (3.5–)4.5–5(–6) x 2–3 µm X. nigripes
    8. Ascospores 5.5–7(–7.5) x 3–3.5 µm X. arenicola
9. Ascospores strongly inequilateral, (5–)5.5–7 x 3 x 3.5–4(–4.5) µm, not surrounded by a gelatinous sheath, with a spore-length germ slit X. piperiformis
9. Ascospores not strongly inequilateral, surrounded by a gelatinous sheath, with less than to slightly less than spore-length germ slit 10
    10. Ascospores light brown to brown, 7–8 x 3.5–4 µm X. brasiliensis
    10. Ascospores dark brown, (7–)8–9.5 x 3–4 µm X. readeri


   EXCLUDED OR DOUBTFUL TAXA
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 TAXONOMY
 KEY TO TAXA
 EXCLUDED OR DOUBTFUL TAXA
DISCUSSION
 LITERATURE CITED
 
Sclerotium stipitatum Berk. & Curr., Trans. Linn. Soc. 23:91 & 93. 1860.

INDIA. Travancore, on ground, 1860, Waring E.J. (K[M] 125991 HOLOTYPE).

Dennis (1961)Go considered this to be a synonym of X. nigripes. It is known that X. escharoidea arises from a sclerotium, but whether or not X. nigripes sensu novo, non al. arises from sclerotia is unknown.

Xylaria flagelliformis Curr., Trans. Linn. Soc. London, ser. II, Bot., 1:129. 1876.

INDIA. Sittang Valley, along the base of Pegu Yomah, on earth, May 1871, Kurz, S. 3485 (K[M] 125995 HOLOTYPE).

Dennis (1961)Go considered this to be a synonym of X. nigripes. The holotype at K is sterile.

Xylaria peperomioides P. Henn., Hedwigia 40:340. 1901.

INDIA. on ground, 16 Jul 1900, Gollan, W., ex Herb. Sydow (S [F41258] LECTOTYPE).

The type at S is sterile. Dennis annotated it as " = Xylaria nigripes (Klotzsch) Sacc." J.D.R. examined a photograph of the type in K ex herb. Sydow. It is annotated by Dennis as " = ?X. nigripes." Hennings (1901)Go described the ascospores as "ellipsoideis, utrinque rotundatis, atris, 3–3.5 x 2.5–3 µm." This fits almost exactly our concept of the ascospores of X. escharoidea, except that information on the nature of the germination site was not provided.

Xylaria pistillariaeformis P. Beccarini, Ann. Botanica 14:134. 1917.

We have not seen material of this species. However the ascospores are given as 27 x 16 µm (Saccardo 1928Go). Dennis (1958)Go gives the ascospore measurement from the type at the Firenze herbarium 4–4.5 x 3–3.5 x 2.5 µm. This suggests that X. pistillariaeformis is another synonym of X. escharoidea.

Xylaria torrubioides Penz. & Sacc., Malpighia 11:496. 1898.

INDONESIA. JAVA: from termite nest, 836 (PAD ISOTYPE).

The type from PAD is immature. Dennis’ annotation on the packet also indicated that the specimen is immature. Dennis (1961)Go considered this a synonym of X. nigripes. However the description of the ascospores by Penzig and Saccardo (1904)Go cites them as "2.5–3 x 2–2.5, globosoellipticis, atrobrunneis," very like those of X. escharoidea. Moreover it was said to resemble X. gardneri var. minori, likely synonym of X. escharoidea.


   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 TAXONOMY
 KEY TO TAXA
 EXCLUDED OR DOUBTFUL TAXA
 DISCUSSION
LITERATURE CITED
 
We consider this paper to be a first step in understanding the systematics of Xylaria species that inhabit termite nests. Most workers have considered Xylaria spp. to be saprophytes of termite nests and indeed Heim (1977)Go discusses them in a chapter titled "Les Saprophytes des meules." Of note, a Xylaria called X. nigripes has been implicated as a gut-associated organism in termites (Sreerama and Veerabhadrappa 1993Go). We strongly suspect that at least some Xylaria spp. associated with termite nests are involved with the economy of the insect, either directly as food or in the capacity of substrate alteration (see Batra and Batra 1979Go, see also refs. in Heim 1977Go). We hypothesize that the tiny ascospores of certain Xylaria species (e.g. X. escharoidea, X. furcata, X. nigripes) are ingested by termites and that these small-spored taxa have evolved with the insect. Other species with larger ascospores are possibly associated with nests in a purely saprophytic way or in some other less obvious ways.

We think that Boedijn (1959)Go and Dennis (1961)Go respectively were correct in believing that several small-spored species are different enough from other Xylaria species to be placed in a new genus or subgenus. These include X. escharoidea, X. furcata, and X. nigripes and perhaps others that are horny in texture when dry and exhibit a dark stromatal core. We consider X. piperiformis, although it has rather small ascospores, to be only distantly related to the dark-cored species, but to be ecologically convergent as a termite associate. We listed under X. nigripes a number of collections with larger ascospores than we consider typical for the species. At present, we have no formal disposition for them. If additional collections convince us that X. arenicola—the name based on the sandy type habitat—is indeed a variety of X. nigripes, some of the large-spored collections could be disposed there. There are also among these some probable new species, but additional collections are required for analysis.

In addition to those taxa that are constantly associated with termites, others are undoubted opportunistic saprophytes taking nutrition from the lignicolous nests.

Some of the unsettled conjectures and questions posed by this study will be answered as additional collections and observations are made, cultures established and molecular characterizations done. We are pursuing these problems.


   ACKNOWLEDGMENTS
 
PPNS 0397. Department of Plant Pathology, Washington State University. The authors are grateful to the curators of BPI, BR, FH, K, S for loaning specimens and to Begoña Aguirre-Hudson (K), Burghard Hein (B), and Mark Spencer (BM) for trying to locate the Klotzsch material of X. nigripes. We thank Svengunnar Ryman (UPS) and Roy Watling (E) for searching for specimens and for information on the protologue of X. furcata, Brian Spooner (K) for information on a collection of T. Petch, and Anna-Lena Anderberg (S) for information on the type material of X. peperomioides. We thank Michael J. Adams, Washington State University, for aid with photography. We dedicate this paper to the memory of R.W.G. Dennis, Franz von Höhnel and Tom Petch, great mycologists who investigated Xylaria from termite nests.


   FOOTNOTES
 
Accepted for publication May 10, 2005.

1 Corresponding author. E-mail: yumingju{at}gate.sinica.edu.tw


   LITERATURE CITED
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 TAXONOMY
 KEY TO TAXA
 EXCLUDED OR DOUBTFUL TAXA
 DISCUSSION
 LITERATURE CITED
 
Batra LR, Batra SWT. 1979. Termite-fungus mutualism. In: Batra LR, ed. Insect-fungus symbiosis-nutrition, mutualism, and commensalism. Montclair, New Jersey: Allan-held, Osmun & Co. p 117–163.

Boedijn KB. 1959. On a new family of the Sphaeriales. Persoonia 1:15–19.

Cesati V. 1879. Mycetum in initere Borneensi lectorum a cl. Od. Beccari. Atti della R Accademia delle Scienze Fisiche e Matematiche di Napoli 8:1–127 + 3 figure plates.

Dennis RWG. 1956. Some Xylarias of tropical America Kew Bull 1956:401–444.

———. 1958. Some Xylosphaeras of tropical Africa Revista Biol, Lisboa 1:175–208.

———. 1961. Xylarioideae and Thamnomycetoideae of Congo. Bull Jardin Botan État Brux 31:109–154.[CrossRef]

Dixon PA. 1965. The development and liberation of the conidia of Xylosphaera furcata. Trans Brit Mycol Soc 48:211–217.

———. 1985. Conidiogenesis in Padixonia Subram. (Hyphomycetes). Bot J Linn Soc 91:203–217.[CrossRef]

Fries EM. 1851. Novae symbolae mycologicae, in peregrinis terris a botanicis Danicis collectae. Nova Acta Regiae Soc Sci Upsal, ser III, 1:17–136. 1851.

Heim R. 1977. Termites et champignons. Paris: Société Nouvelle des Éditions Boubée. 207 p.

Hennings P. 1901. Fungi Indiae orientalis. II. Hedwigia 40:323–342.

Ju Y-M, Rogers JD. 1999. The Xylariaceae of Taiwan (excluding Anthostomella). Mycotaxon 73:343–440.

Lloyd CG. 1924. Mycological notes No. 71. Mycol Writings 7:1237–1268.

Nannfeldt JA. 1972. Camarops Karst. (Sphaeriales, Boliniaceae) with special regard to its European species. Svensk Bot Tidskr 66:335–376.

Penzig O, Saccardo PA. 1904. Icones fungorum Javanicorum. Leiden: E. J. Brill. 124 p. + 80 figure plates.

Petch T. 1906. The fungi of certain termite nests. Ann Roy Bot Gard (Peradeniya) 3:185–270.

———. 1913. Termite fungi: a résumé. Ann Roy Bot Gard (Peradeniya) 5:303–341.

Rayner RW. 1970. A mycological colour chart. Kew: Commonwealth Mycological Institute. 34 p. + charts I & II.

Saccardo PA. 1899. Sylloge fungorum omnium hucusque cognitorum. XIV. Patavii (Typis Seminarii). 1316 p.

———. 1928. Sylloge fungorum omnium hucusque cognitorum. XXIV, sect. II. Abellini (Typis Pergola). p 705–1438

Sands WA. 1969. The association of termites and fungi. In: Krishna K, Weesner FM, eds. Biology of termites. Vol. 1, ch. 16. New York: Academic Press. p 495–524.

San Martín F. 1992. A mycofloristic and cultural study of the Xylariaceae of Mexico. [Doctoral dissertation]. Washington State University. 560 p.

Sreerama L, Veerabhadrappa PS. 1993. Isolation and properties of carboxylesterases of the termite gut-associated fungus, Xylaria nigripes K., and the identity from the host termite, Odontotermes horni. W., mid-gut carboxylesterases. Internat J Biochem 25:1637–1651.[CrossRef]

Subramanian CV. 1972. Padixonia, a new genus of Hyphomycetes. Curr Sci 41:282–283.

von Höhnel F. 1908. Fragmente zur Mykologie (V. Mitteilung, Nr. 169 bis 181). Sitzungsber Kaiserl Akad Wiss, Math-Naturwiss Klasse, Band 117:1–48 + Tafeln 1–4.




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