A COMPARATIVE STUDY OF THE TYPES OF THREE SPECIES OF MYXOMYCETES: TRICHIA CRATERIFORMIS, T. FALLAX VAR. OLIVACEA AND T. FERNBANKENSIS G. MORENO & A. CASTILLO Departamento de Biología Vegetal, Facultad de Biología, Universidad de Alcalá, Alcalá de Henares, E-28871 Madrid gabriel.moreno@uah.es; aurelio.castillo@uah.es Summary. MORENO, G. & A. CASTILLO (2013). A comparative study of the types of three species of Myxomycetes: Trichia crateriformis, T. fallax var. olivacea and T. fernbankensis. Bol. Soc. Micol. Madrid 37: 85-98. The type of Trichia crateriformis was examined with light and electron microscopy and compared with a lectotype of Trichia fallax var. olivacea. The two taxa are here considered to be conspeciic. Also, the type of Trichia fernbankensis was examined with light and electron microscopy and is a synonym of Trichia decipiens. Keywords: Amoebozoa, Myxomycota, scanning electron microscopy, taxonomy, type material. Resumen. MORENO, G. & A. CASTILLO (2013). Un estudio comparativo de los tipos de tres especies de Myxomycetes: Trichia crateriformis, T. fallax var. olivacea and T. fernbankensis. Bol. Soc. Micol. Madrid 37: 85-98. Se estudia el tipo de Trichia crateriformis con microscopía óptica y electrónica y se compara con el lectotipo de Trichia fallax var. olivacea. Los dos taxones son considerados coespeciicos. También, el tipo de Trichia fernbankensis fue examinado con microscopía óptica y electrónica y es un sinónimo de Trichia decipiens. Palabras clave: Amoebozoa, material tipo, microscopio electrónico de barrido, Myxomycota, taxonomía. INTRODUCTION An examination of type material is fundamental for knowing any species well and this is particulary true for the myxomycetes. However, locating a type specimen may be a dificult task, especially when it is very old material. Sometimes the location of type material was not provided in the original description, or the material may subsequently have been moved. Furthermore, access to a type may be restricted due to its age or Bol. Soc. Micol. Madrid 37. 2013 scarcity of the material. Investigators therefore frequently rely on the original species description or subsequent descriptions made by other investigators who may not have actually examined the type specimen. Older descriptions are often brief and their interpretation may be dificult and ambiguous. As a consequence, misinterpretations of taxa are passed on, as in the case of Lamproderma cribrarioides (Fr.) R.E. Fr., which had been misinterpreted since its description in 1829. The holotype of this species 85 G. MORENO & A. CASTILLO was examined by SINGER & al. (2003) found that corresponds to a new species, L. retirugisporum G. Moreno, H. Singer, Illana & A. Sánchez, that had previously not been properly described. The solutions to various taxonomic problems may depend on the careful study of the type material. Here we continue with this line of research to review taxa in the genus Trichia. We compared the original diagnoses with a reexamination of the type material under SEM, using the technique of critical point drying to examine spores and capillitium which has been essential in obtaining the results presented below. MATERIALS AND METHODS The material is preserved in the herbarium of the Dept. of Plant Biology, University of Alcalá, (AH) and in the herbarium of the National Fungus Collections (BPI). Other specimens were from the herbaria AH, MA-Fungi, and the herbarium of D.W. Mitchell. The collections studied were mounted in Hoyer’s medium. Spores were measured including surface structures such as spines or warts with an oil immersion lens. Light microscopy (LM) was made with a Nikon eclipse 80i microscope equipped with a digital automatic photographic system Nikon DS-5M. The SEM micrographs were made with a Zeiss DSM-950 microscope. For ultramicroscopic studies, the material to be examined was rehydrated in concentrated ammonium hydroxide (28–30%) for 30 minutes, dehydrated in aqueous ethanol (70%) for 30 minutes, ixed for 2 hours in pure ethylene glycol dimethyl ether (= 1,2–dimethoxymethane) and inally immersed in pure acetone for at least 2 hours. This was followed by critical point drying and sputter-coating with gold-palladium. This technique uses very little material (one sporocarp, a part of it or only a small portion of spores). Terminology used to describe spore ornamentation follows that of RAMMELOO (1974, 1975). TAXONOMY Trichia crateriformis G.W. Martin, Mycologia 55: 131 (1963) Figs. 1–10 ≡ T. craterioides G.W. Martin, Brittonia 14: 183 86 (1962) nom. illeg., non T. craterioides Corda, Icon. Fung. 2: 21 (1838) Specimens examined: NEW ZEALAND. Riccarton Bush, South Island, on dead wood, June 1957, P.S. Evans 47 (CANTY, type; portion in IA, now in BPI). Coll. Peter S. Evans, leg. W.R. Philipson 47, BPI 835163 type (isotype; this material is a portion sent to IA and currently deposited in BPI). Two ixed slide preparations indicate the typus, BPI 835156. Observations: The type (BPI 835163) is on a woody substrate attached to the lid of a cardboard box and consists of a group of approx. 12 sporocarps with stipes of 1–1.5 mm total height, some of which are in poor condition. Sporotheca green olive and 0.75–1 mm diam. (Fig. 3). Dehiscence is well marked by means of a circular area in almost all of the sporocarps (Fig. 4). Stipe cylindrical, 0.5–0.75 mm in height, dark to almost black, with the interior filled with cell-like bodies, 13–20 µm diam. Capillitium formed of pale yellow elaters 7–8 µm in diam. and 3–4 broad and smooth, long-tipped spirals (Figs. 5-7). Spores 11–12.5 µm diam., globose, without refractive bodies, pale yellow, spinulose to crested, with the ornamentation evenly distributed, wellmarked and approx. 1 µm high. In phase-contrast the crests are easily observed. Under SEM the spore ornamentation is cristate and is formed by broad-based ridges that join to form short crests with irregular and sinuous morphology (Figs. 8-10). Sometimes they join towards the apex to assume a stellate or reticulate appearance. The capillitial elaters under SEM are smooth and with tightly-packed spirals (Figs. 5-7). In addition, two slides remain in a separate box (BPI 835156), one with a circular coverslip, the other with a square coverslip and labelled as Trichia craterioides, the epithet chosen by MARTIN (1962) subsequently called T. crateriformis (MARTIN, 1963). On both it is indicated that the specimen consists of type material. In the abovementioned slide preparations and with the effect of the years passed, LM observations show the elaters to be more than 250 µm in length and 5–6 µm diam., ornamented with broad spirals and Bol. Soc. Micol. Madrid 37. 2013 A COMPARATIVE STUDY OF THE TYPES OF THREE SPECIES OF MYXOMYCETES: TRICHIA CRATERIFORMIS, T. FALLAX VAR. OLIVACEA AND T. FERNBANKENSIS Figs. 1-10 Trichia crateriformis type. 1. Label on the box in which the collection was conserved. 2. Two ixed preparations which indicate the type deposited in BPI. 3. Sporocarps. 4. Detail of the circumscissile dehiscence of the sporocarps. 5-6. Endings of the elaters. 7. Smooth spirals of the elaters. 8-9. Spores as viewed by SEM. 10. Detail of spore ornamentation as viewed by SEM. Scale bars: 3-4 = 1 mm, 5-7 = 5 µm, 8-9 = 2 µm, 10 = 1 µm. Bol. Soc. Micol. Madrid 37. 2013 87 G. MORENO & A. CASTILLO with tapered tips more than 25 µm long. Spores are collapsed and approximately 10–11 µm in diam., pale yellow, spinulose and with short wellmarked crests. There are few records of Trichia crateriformis. The type locality is in New Zealand and there are other records from Tierra del Fuego in Argentina (ARAMBARRI, 1975), Austria (SCHUSSLER, 1975) and India (LAKHANPAL & MUKERJI, 1981). NEUBERT & al. (1993: 197-198) and WANG & LI (2006, plate 48). Trichia decipiens var. decipiens (Pers.) T. Macbr., N. Amer. Slime-Moulds: 218 (1899) Figs. 11-22. ≡ Arcyria decipiens Pers., Ann. Bot. (Usteri) 15: 35 (1795) = Trichia fallax Pers., Observ. Mycol. 1: 59 (1796) Observations: The type material is well preserved with numerous clustered, pyriform sporocarps, on remains of wood that contain abundant capillitium and spores. The sporocarps are short stalked. Sporotheca 0.6-1 mm in diam., subglobose to ovoid with greenish yellow to greenish brown shades (Fig. 24). Peridium single, thin, translucent, with apical circumcissile dehiscence that breaks to leave the sporocarp in the shape of a deep calyculus with regular edges. Operculum membranous, similar in structure to that of the calyculus (Fig. 25). Stalk short, darker than the sporotheca and tapered towards the base. Capillitium 7-8 µm diam., formed of yellowish elaters with thick, unbranched, smooth spirals and long-tapered tips (Figs. 26-27). Spores 11-12 µm diam., globose to subglobose, pale yellowish, verruculose to shortly crested and which are seen well in phase contrast. By SEM the spore ornamentation is cristate and the crests have an irregular morphology, formed by being linked to each other by bacula with a broader base (Figs. 28-30). When the bacula are joined at the apex they take a stellate or subreticulate appearance, sometimes leaving small complete circles (Figs. 32-33). The elaters of the capillitium have smooth, closely spaced spirals with long, sinuous tips (Figs. 2627). The inner surface of the peridium is smooth (Fig. 31). Specimens examined: MEXICO. on woody debris, MEXU 11292 in AH 31771. JAPAN, Mt. Tskura, Namischo, Fukushima Pref., coll. M. Hario, 22.10.1996, YY 16456 with duplicate in DWM 5315. Observations: It is characterized by its pyriform or globose form and the brown to greenish brown colour of the sporotheca (Fig. 11). Stalk shorter and darker than the sporotheca (Fig. 12). Peridium membranous, iridescent and translucent, with irregular dehiscence at the apex that persists at the base as a calyculus with irregular edges (Fig. 13). Capillitium formed of elaters with smooth spirals and of equal diam. that are tapered towards the ends (Figs. 14-15). We emphasize this particular spore ornamentation by LM, formed by a complete reticulum of small meshes per hemisphere and with warts and crests in the remaining surface. SEM studies confirm the existence of this contrasting type of spore ornamentation between hemispheres (simple reticulate and cristate) (Figs. 16-22). In addition, we observe that the walls of the meshes are of uniform width and height, without having hollows or perforations. Sometimes the interior of the mesh has small free projections that are not anastomosed. The meshes have a variable morphology with a width up to 2 µm. This type of ornamentation has also been observed using SEM by HATANO (1986, plate 21), 88 Trichia fallax var. olivacea Meyl., Bull. Soc. Vaud. Sci. Nat. 44: 300 (1908) Figs. 23-33. Specimen examined: SWITZERLAND. Deneriaz-Dessus, Le Chasseron, Canton Vaud, on dead wood, 1300 m, leg. C. Meylan, X-1908, lectotype myxo 069 herbarium C. Meylan in LAU. Trichia decipiens var. olivacea (Meyl.) Meyl., Bull. Soc. Vaud. Sci. Nat. 55: 244 (1924) Specimens examined: CUBA. on logs, 1857, leg. C. Wright, ex folder 193, nº 546 Curtis Fungus Herbarium, FH, as T. varia. SPAIN. Badajoz, Azuaga, Arroyo Argallón, on dead wood of Bol. Soc. Micol. Madrid 37. 2013 A COMPARATIVE STUDY OF THE TYPES OF THREE SPECIES OF MYXOMYCETES: TRICHIA CRATERIFORMIS, T. FALLAX VAR. OLIVACEA AND T. FERNBANKENSIS Figs. 11-22 Trichia decipiens var. decipiens DWM 5315. 11-12. Sporocarps. 13. Detail of the irregular dehiscence of the sporocarp. 14. Smooth spirals of the elaters. 15. Endings of the elaters. 16-17 and 19-22. Spores as viewed by SEM forming a complete reticulum of small meshes in one hemisphere and with warts and crests on the remaining surface. 18. Detail of the complete reticulum ornamentation of spore as viewed by SEM. Scale bars: 11-13 = 0.5 mm, 14-15 = 5 µm, 16-17 and 19-22 = 2 µm, 18 = 1 µm. Bol. Soc. Micol. Madrid 37. 2013 89 G. MORENO & A. CASTILLO Figs. 23-33 Trichia fallax var. olivacea lectotype. 23. Label on the box in which the collection was conserved. 24. Sporocarps. 25. Detail of the circumscissile dehiscence of the peridium. 26. Elater tip. 27. Smooth spirals of the elater. 28-29. Spores as viewed by SEM formed by short crests. 30. Detail of the crested ornamentation of a spore viewed by SEM. 31. Detail of the inner peridium AH 14899. 32-33. Spores as viewed by SEM formed by short crests AH 14899. Scale bars: 24-25 = 1 mm, 26-27 = 5 µm, 28-29 and 32-33 = 2 µm, 30 = 1 µm. 31 = 50 µm. 90 Bol. Soc. Micol. Madrid 37. 2013 A COMPARATIVE STUDY OF THE TYPES OF THREE SPECIES OF MYXOMYCETES: TRICHIA CRATERIFORMIS, T. FALLAX VAR. OLIVACEA AND T. FERNBANKENSIS Populus alba, leg. J.R. García, 10.4.1991, AH 13200. Ibidem on woody debris of Nerium oleander, 27.12.1991, AH 16317. Ibidem 2.2.1992, AH 16314. Ibidem on dead wood of Quercus sp., 31.5.1993, AH 16483. Barcelona, Santa Fé del Montseny, on woody debris of deciduous, leg. G. Moreno and C. Illana, 17.10.1989, AH 12187. Burgos, Villafranca Montes de Oca, on wood of Fagus sylvatica, leg. A. Castillo, 6.10.1991, AH 14700. Ibidem leg. A. Castillo and I. Sevilla, 25.7.1993, AH 16224. San Miguel de Pedroso, on wood of Quercus faginea, leg. A. Castillo, 15.8.1992, AH 14812. Fresneda de la Sierra, on wood of Fagus sylvatica, leg. A. Castillo, 7.11.1992, AH 15352. Cáceres, Sierra de Bernabé del Piornal de Tormantos, on woody debris of Castanea sativa, leg. R. Galán, 11.11.1987, AH 12348. Ibidem leg. G. Moreno and C. Illana, 28.11.1988, AH 11415. Cantabria, Parque Natural del Saja-Besaya, Ucieda de Arriba, on wood of Fagus sylvatica, 28.8.1996, 315 m, leg. A. Sánchez, AH 30309. Mirador Cruz de Cabezuela, Polaciones, on wood of Fagus sylvatica, 15.9.1999, 1150 m, leg. A. Sánchez, AH 30310. Córdoba, Argallón, Finca Las Canalejas, on woody debris of deciduous, leg. J.R. García, 8.12.1990, AH 12699. Guadalajara, Aldeanueva de Atienza, river Pelagallinas, on wood of Pinus sylvestris, leg. A. Castillo, 17.11.1993, AH 16393. La Rioja, Ezcaray, near to resort of Vadezcaray, on wood of Fagus sylvatica, leg. A. Castillo, 15.3.1992, AH 14899. Lérida, Sorpe, Pto. de la Bonaigua, on wood of Abies alba, leg. F. Esteve-Raventós, A. Altés, V. González and C. Illana, 3.10.1991, AH 13844. Madrid, Montejo de la Sierra, on wood of Rosaceae, leg. G. Moreno and A. Castillo, 30.4.1992, AH 14807. Ibidem on wood of Fagus sylvatica, AH 14808. Ibidem on wood of Quercus pyrenaica, AH 14809. Puerto de Cotos, on wood of Pinus sylvestris, 4.7.1998, 1900 m, leg. A. Sánchez, AH 19160. Málaga, Cortes de la Frontera, Pto. de Galis, La Sauceda, on wood of Quercus suber, leg. M.T. Vizoso and C. Illana, 11.12.1990, AH 13078, AH 13080. Segovia: Puerto de la Quesera, Riofrío de Riaza, on wood of Fagus sylvatica, 13.12.1997, 1550 m, leg. A. Sánchez, AH 19161. Ídem, 1.11.1999, 1500 m, AH 28866. Ídem, 1.11.2000, 1600 m, AH 28863. Valsaín, on Bol. Soc. Micol. Madrid 37. 2013 lumber, 23.5.1998, 1500 m, leg. A. Sánchez, AH 30327. Garden of Palacio, San Ildefonso de La Granja, on lumber, 8.2.1999, 1500 m, leg. A. Sánchez, AH 30328. Caballar, on wood of Populus sp., 17.2.2001, 1030 m, leg. A. Sánchez, AH 28835. Puerto de la Quesera, Riofrío de Riaza, on wood of Fagus sylvatica, 9.7.2000, 1500 m, leg. A. Sánchez, AH 30330. Ídem, 1.11.2000, 1650 m, AH 28883. Tenerife (Canary Islands): Monte de los Silos, Teno, on broadleaf stick, 28.3.78, DWM 3199. Las Mercedes, on rotting wood, leg. C.L. Champion, 16.3.1975, DWM 1918. Monte de los Silos, Teno, on dead wood; 28.3.78, DWM 3201. Los Organos, on dead wood of Pinus canariensis, 29.3.78. DWM 3224. Zaragoza, Moncayo, 1110 m, on wood of Quercus pyrenaica, leg. M. Lizárraga and D. Cuadrado, 22.1.2005, AH 34168, AH 34169, AH 34170, AH 34172, AH 34173. UNITED KINGDOM. Lavender Platt, Ashdown Forest, East Sussex, Vice-county 14, on dead wood of Fagus sylvatica; National Grid Reference TQ3933, 20.8.1970, DWM 678. Paternoster Wood, Coleman’s Hatch, East Sussex, Vc. 14, on dead wood of Quercus robur; TQ4534, 2.10.1971, DWM 1018. Pam’s Wood, Horsted Keynes, East Sussex, Vc. 14, on dead wood of Quercus robur; TQ3728, 26.3.1972, DWM 1185. Great Yews, South Wiltshire, Vc. 8, SU1122, on dead wood, 16.3.1975. DWM 1870. Near Dores by Loch Ness, Easterness-with-Nairn, Scotland, Vc. 96, on dead wood, NH5934, 1.8.1975, DWM 2045. Winkhurst Green, West Kent, Vc. 16, on dead wood, TQ4950, 20.2.1977, DWM 2890. Alexandra Park, Hastings, East Sussex, Vc. 14, on dead Ulmus, TQ8010, 10.2.80, DWM 3447. Bouldner Plantation, Isle of White, Vc. 10, oak branch on the ground; SZ3789, 25.8.1980, DWM 3508. Near Rushar’s Cross, Mayfield, East Sussex, Vc. 14, on dead wood, TQ5928, 15.3.1997, DWM 5227. Hartfield, East Sussex, Vc. 14, on dead wood; TQ4835, I.7.1997, DWM 5292. Observations: Trichia decipiens var. olivacea is characterized by its brown to olive-brown, often globose sporothecae. Peridium membranous, with well-defined circumscissile operculate apical dehiscence which persists as a calyculus with smooth edges. Operculum membranous, similar 91 G. MORENO & A. CASTILLO to the structure of peridium of the calyculus, sometimes with indentations on its inner surface by pressure of spores. By LM the spore ornamentation is formed by warts, papillae or short irregular ridges across its surface. By SEM the spore ornamentation is similar to that of Trichia crateriformis and consists of bacula that join to form short ridges with irregular and sinuous morphology, the base appearing to be broadly columnar, irregular and sometimes attached to the reticulate apex and then taking a stellate appearance. The elaters of capillitium have smooth, tightly packed spirals. This type of spore ornamentation has also been observed by SEM HATANO 1986 (plate 21) and NEUBERT & al. (1993: 198). Trichia fernbankensis Frederick, R. Simons & I.L. Roth, Trans. Brit. Mycol. Soc. 83(2): 369 (1984) Figs. 34-43 Specimens examined: USA. Atlanta, Georgia, Fernbank Science Center, DeKalb Country, mixed hardwood forest, on rotting wood, 22.11.1976, leg. R. Simons, det. M.L. Farr as Trichia crateriformis, BPI 71875 (835155) Holotype. Idem (2 sporocarps metallic by SEM) BPI 835157 Isotype. Observations: The type material is well preserved. On the remains of wood are two groups of sporocarps, one with 11 sporocarps and the other with 4 sporocarps. Sporocarps stalked, 1.5-2 mm total height (Fig. 36). Sporotheca approximately 1 mm in diam., brown to brownish yellow in colour, with apical dehiscence more or less circumcissile to irregular but not always clearly circumsissile as indicated FREDERICK & al. (1984). Operculum membranous, similar to the structure of the calyculus, sometimes with indentations on its inner surface caused by pressure of spores (Fig. 36). Stipe cylindrical, 1-1.5 mm of height, strongly ridged, dark brown (Fig. 36). Hypothallus dark-brown, thin, common to groups of sporocarps. Capillitium abundant, 4-5 µm diam., formed by free elaters, pale yellow, smooth spirals and long-tapered ends (Figs. 3738). Spores 8-10(-12) µm diam., globose, pale yellow in LM, formed by a complete reticulum 92 of small meshes per hemisphere and with warts and crests in the remaining surface (Figs. 3943). SEM studies conirm the existence of this contrasting type of spore ornamentation between hemispheres (simple reticulate and cristate). DISCUSSION PERSOON (1795), in his description of the macroscopic characters of Arcyria decipiens, hesitated to assign this taxon to the genus Trichia, possibly because the elaters present in Trichia were not recognized as a character to differentiate the genus from the capillitium of Arcyria. The following year, PERSOON (1796) described Trichia fallax having doubts regarding the similarity of this species with Arcyria. He also used the same iconography in both publications to describe the two species (A. decipiens and T. fallax). At this time the characters to delimit Trichia and Arcyria were very subjective and undeined. LISTER (1894), in the irst edition of his book, synonymised Arcyria decipiens with Trichia fallax, using the latter epithet to refer to this species although it had priority over A. decipiens. MACBRIDE (1899) later prioritized Trichia decipiens over T. fallax by the relevant combination and, for this species, described the spores as “delicatelly minutely reticulate, 10-12 μm” and stating that “this is, of course, our familar T. fallax of all authors from Persoon down”. But this author failed to mention the type of dehiscence of the peridium in his description (either irregular or preformed by a line). From this date onwards, most authors such as LISTER (1925), MARTIN & ALEXOPOULOS (1969), HAGELSTEIN (1944) and NANNENGA-BREMEKAMP (1991) used this combination. Trichia decipiens s. lato is a common taxon with cosmopolitan distribution (MARTIN & ALEXOPOULOS, 1969) and fruiting mainly on woody debris. Within this concept we can include variations that are manifested in the morphology and colour of the sporotheca, peridium type, size, capillitium morphology and spore ornamentation. Hence some authors such as NANNENGA-BREMEKAMP (1991), LADO & Bol. Soc. Micol. Madrid 37. 2013 A COMPARATIVE STUDY OF THE TYPES OF THREE SPECIES OF MYXOMYCETES: TRICHIA CRATERIFORMIS, T. FALLAX VAR. OLIVACEA AND T. FERNBANKENSIS Figs. 34-43 Trichia fernbankensis type. 34. Label on the box in which the holotype was conserved. 35. Label on the box in which the isotype was conserved. 36. Sporocarps. 37. Smooth spirals of the elater. 39. Ending of the elater. 39-40. Spores as viewed by SEM formed by a complete reticulum of small meshes in a hemisphere. 41. Spores as viewed by SEM formed by a complete reticulum of small meshes in one hemisphere and with warts and crests on the remaining surface. 42-43. Spores as viewed by SEM formed by short crests. Scale bars: 36 = 1 mm, 37 = 5 µm, 38 = 10 µm, 39-43 = 2 µm. Bol. Soc. Micol. Madrid 37. 2013 93 G. MORENO & A. CASTILLO PANDO (1997) and ING (1999) have recognized at least two varieties T. decipiens var. decipiens and T. decipiens var. olivacea, while others such as MARTIN & ALEXOPOULOS (1969) and FARR (1976) regarded them as a single species with variable morphology. Tables I and II show the differences indicated in the descriptions of previous authors. Introducir tabla 1 y tabla 2 If one looks closely at the differences in the two tables, it can be seen that regarding the morphology of the sporotheca the authors agree to separate T. decipiens var. olivacea by its morphology being almost spherical, subglobose to globose, while T. decipiens var. decipiens has a turbinate morphology, ovate to pyriform. However, LADO & PANDO (1997) also describe the latter as being subglobose. Regarding the dehiscence of the peridium, that of T. decipiens var. olivacea is clearly circumcissile and leaving a calyculus, while in T. decipiens var. decipiens it is irregular but also leaves a calyculus. Regarding the colour of the sporotheca of T. decipiens var. olivacea, authors have included the olive-coloured, less yellowish or ochraceous appearance which is unlike that of T. decipiens var. decipiens. Regarding the capillitium, those authors who cite the var. olivacea, do not provide measurements or data to indicate differences. In T. decipiens var. decipiens there is a large variation in the width of capillitium according to the authors listed, varying from 4.5-5.5 μm diam. (LISTER, 1925; NANNENGA-BREMEKAMP, 1991) to 6-7 μm in diam. (LADO & PANDO, 1997). The spores do show differences in size but, nevertheless in T. decipiens var. olivacea, the spore ornamentation is warted while in T. decipiens var. decipiens it is delicately reticulate over part of the surface. Some authors have mentioned the two varieties as appearing to represent forms rather than important varieties (LISTER, 1925) or to be of little taxonomic value (LADO & PANDO, 1997). In our view the main differences used to separate the two taxa are the smaller size of the sporocarps of T. decipiens var. olivacea, dehiscence of the peridium being clearly circumcissile and remaining as a calyculus with a regular margin and having non-reticulate spore ornamentation. 94 On the other hand, T. decipiens var. decipiens is characterized by its larger sporocarps, irregular dehiscence and persisting in the lower part as a cup or funnel with an irregular edge. Also the spore ornamentation is very different with half of the spore surface having a delicate complete reticulum and the other with a crested ornamentation similar to that of T. decipiens var. olivacea. Thus we observed spores with different spore ornamentation, a reticulate ornamentation and another completely crested, depending on the spore orientation. This feature of T. decipiens var. decipiens spores is difficult to see by LM and is the character that has probably confused those who have not recognised the differences or have simply treated the variations as forms or varieties. KOWALSKI (1975) reviewed material described by Meylan as Trichia fallax var. olivacea and created a lectotype. His observations agree with those of Meylan and he came to the conclusion that “T. fallax var. olivacea is a distinct taxon and should be recognized because T. decipiens var. decipiens is much yellower in color, longer stalked, and it has a peridial apex that tears irregularly, leaving at most a highly roughened opening”. While for T. fallax var. olivacea he stated that “by being olivaceous instead of tawny yellow, smaller in size, and by having a dull, evanescent, apical cap to the sporangium that left a perfectly smooth, round opening upon disappearance”. However, neither Meylan nor Kowalski mention differences in spore ornamentation. HATANO (1986) and NEUBERT & al. (1993) presented SEM images of the spore of Trichia decipiens var. decipiens and T. decipiens var. olivacea but did not show the different spore ornamentation present in each hemisphere of T. decipiens var. decipiens. Trichia decipiens may be confused with Hemitrichia clavata (Pers.) Rostaf. by the shape of its sporocarps, hemitrichioid capillitium consisting of a few, very long unbranched elaters with almost no free ends and different spore ornamentation. FREDERICK & al. 1983, stated that “the operculum of Trichia crateriformis consists of a single layer of spore-like bodies that have the cell Bol. Soc. Micol. Madrid 37. 2013 A COMPARATIVE STUDY OF THE TYPES OF THREE SPECIES OF MYXOMYCETES: TRICHIA CRATERIFORMIS, T. FALLAX VAR. OLIVACEA AND T. FERNBANKENSIS Table I.- Main features of Trichia decipiens var. decipiens according to different authors. * Only describe T. decipiens s. lato T. decipiens var. decipiens Morphology sporotheca Peridium Colour sporotheca Macbride (1899) Turbinate No mention to peridial features or dehiscence Shining olive or olivaceous brown Lister (1925) Turbinate Breaks up leaving a circular opening Shining olive or yellow-brown Martin & Alexopoulos (1969)* Turbinate Persisting below as a deep or sometimes rather shallow cup. Irregular dehiscence Shining olive or olivaceous brown Farr (1976)* Turbinate to pyriform, occasionally goblet-shaped Thicker below, persisting as a deep to moderately shallow calyculus. No mention to dehiscence system of sporotheca NannengaBremekamp (1991) Ovate or pyriform Lado & Pando (1997) Capillitium Tapering gradually to the long, 20-40 µm, slender apices. 4.5-5.5 µm, gradually tapering into long slender points Spores Minutely, delicately reticulate, 10-12 µm Either minutely warted or very closely and often irregularly reticulated on one side, 9-12 µm 5-6 µm, slender tips 10-13 µm, bearing a delicate reticulation Shining olive to olivaceous yellow or brown 5-6 µm, tapering gradually to the long, slender tips 10-13 µm, faintly and delicately reticulate over part or most of the surface Dehiscing irregularly at the apex leaving a basal cup Ochraceous to orchraceous brown 4.5-5.5 µm, gradually attenuate into very long points 10-13 µm, with short irregular ridges and an interrupted reticulum with small meshes Subglobose to pyriform Usually remaining as a basal deep funnel- or trumpetshaped calyculus, border usually rolled backwards and/or torn. Irregular or circumscissile dehiscence Olive brown or strong yellowish brown or strong orange yellow 6-7 µm, free ends are pointed, 70100µm long 11-13 µm, faintly reticulate, fragmented and finemeshed Ing (1999) Top-shaped Dehiscing at about midheight, either by a performed fissure, leaving a cup below and a lid above Shining olive or yellow- brown 5-6 µm, tapering to long thin points 10-13 µm, marked with a delicate reticulation over much of the surface, the rest minutely warted. As Trichia fernbankensis (Frederick et al. (1984) Turbinate Operculum appearing smooth mooth separating irregularly or circumscissile at a performed dehiscence line Honey-coloured 4-5 µm diam. with 2-3 smooth to finely roughened spirals and long tapering ends 8-10 (-12) µm, distinctly reticulate with ridges low and narrow Bol. Soc. Micol. Madrid 37. 2013 95 G. MORENO & A. CASTILLO Table II.- Main features of Trichia decipiens var. olivacea according to different authors. T. decipiens var. olivacea Morphology sporotheca Peridium Colour sporotheca Lister (1925) No mention morphology of sporotheca Clean circular opening No mention colour of sporotheca NannengaBremekamp (1991) almost spherical clearly marked, dull, regular lid at the top olive or olivebrown Lado & Pando subglobose (1997) With calyculus and dehiscence clearly circumscissile Olivaceous Ing (1999) Circumscissile dehiscence, as if by a performed lid Olive and more or less yellow Globose wall ornamented with warty excresences similar to those of the spores”, noting that this ornamentation could be unique for the Myxomycetes. In our opinion, and in view of the SEM photographs of the operculum published by them and after examination of type material of T. crateriformis, we conclude that this unusual structure of the operculum consists of tightly collapsed spores, especially as the type material is in poor condition. The technique used for SEM in that paper did not use the critical point method: Fruiting body structures of Myxomycetes are not formed by cells, except for the spores. Trichia fernbankensis as we see in the igures (34-43) is a synonym of T. decipiens. The holotype is deposited in BPI with the two numbers 71875 (835155) which must be retained only by the number BPI 71875 as indicated by FREDERICK & al. (1984) in their publication. The sample’s label (ig. 34) reads “Trichia crateriformis”, while it should be “T. fernbankensis holotype”. In conclusion, regarding the dehiscence of the sporotheca, we are able to establish two groups among the species studied of the genus Trichia: Group 1 with irregular dehiscence: Trichia fernbankensis and Trichia decipiens var. decipiens. Group 2 with regular dehiscence: Trichia crateriformis is well marked by means of a circular area, T. fallax var. olivacea with apical circum- 96 Capillitium No mention of capillitium or characteristic Spores No mention of spore characteristics Rather widely dispersed, irregular, low warts Warted, with no trace of reticulum cissile dehiscence and T. decipiens var. olivacea has well-defined circumcissile operculate apical dehiscence. Regarding the spore ornamentation, we conclude that there are two distinct types in the genus Trichia studied. The ornamentation formed by a reticulum on only half of the spore surface, while the other hemisphere has crested warts and another type of spore ornamentation consisting only of crested warts without forming a reticulum. There is no variation in spore ornamentation between the two groups. First group: Trichia decipiens and T. fernbankensis. Second group: Trichia crateriformis, T. fallax var. olivacea and T. decipiens var. olivacea. TAXONOMIC CONCLUSIONS After detailed studies and analysis of the material we propose the synonymy between T. crateriformis and T. decipiens var. olivacea, and also between Trichia decipiens and T. fernbankensis. 1.- Trichia decipiens (Pers.) T. Macbr., N. Amer. Slime-Moulds: 218 (1899) ≡ Arcyria decipiens Pers., Ann. Bot. (Usteri) 15: 35 (1795) = T. fernbankensis Frederick, R. Simons & I.L. Roth, Trans. Brit. Mycol. Soc. 83(2): 369 (1984) Bol. Soc. Micol. Madrid 37. 2013 A COMPARATIVE STUDY OF THE TYPES OF THREE SPECIES OF MYXOMYCETES: TRICHIA CRATERIFORMIS, T. FALLAX VAR. OLIVACEA AND T. FERNBANKENSIS 2.- Trichia crateriformis G.W. Martin, Mycologia 55 (1):131 (1963) = T. fallax var. olivacea Meyl., Bull. Soc. Vaud. Sci. Nat. 44: 300 (1908) = T. decipiens (Pers.) T. Macbr. var. olivacea (Meyl.) Meyl., Bull. Soc. Vaud. Sci. Nat. 55: 244 (1924) = T  . decipiens f. olivacea (Meyl.) Y. 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