taxonID	type	description	language	source
487C87B0FFC2FE25FF16C4FF09578EF8.taxon	description	This species is commonly noted as the most dominant in xeric environments (Novozhilov et al. 2003, Lado et al. 2007 a, 2011, Estrada-Torres et al. 2009). Most of the specimens were found on Opuntia rufida and Opuntia sp. cladodes. In Colorado Plateau, Novozhilov et al. (2003) reported B. melanospora mainly on remains of genus Opuntia. b, c Collaria biasperospora (Kowalski) Dhillon & Nann. - Bremek. ex Ing. [0, 2] Figs 20 – 26 Loc 11: On Y sp. leaves, JRM 202, 24 October 2008, (mc, pH = 7.8), JRM 204, 22 November 2008, (mc, pH = 7.8). The sporocarps are stalked and scattered, up to 1.7 mm total height. Sporotheca globose, 0.3 mm diam. (Fig. 20). The peridium is membranous, iridescent, single, evanescent, violaceous brown by transmitted light, and irregular dehiscence with a well-defined collar at the base of the sporotheca. With a hollow stalk (Fig. 26), smooth, dark, brilliant, up to 1.0 mm height and with a characteristic reddish fibrous base, which reaches the middle of the stalk. The capillitium is dense, rigid, it arises from columella apex, dark brown, branching and anastomosed toward the periphery to form a net with free ends (Fig. 21). The spores are globose, 7.4 – 8.7 µm diam., violaceous brown in transmitted light, with clusters of dark conspicuous warts (Figs. 22 – 25). Our specimens agree with the description of Lamproderma biasperosporum (≡ Collaria biasperospora) Kowalski (1970), who pointed out that it is closer to L. arcyrionema Rostaf., yet, the main difference is the dense flexuose capillitium in L. arcyrionema in comparison with the dense rigid capillitium of L. biasperosporum. Kowalski also indicated that the capillitium apex is paler, against the Mapimí specimens that are uniformly coloured in the rest of capillitium. Besides, L. arcyrionema grows frequently in groups, whereas L. biasperosporum has a more dispersed growth. According to Kowalski (1970) L. biasperosporum is very common in alpine areas, although it can also be found in low elevations, associated with lianas. In this study it was found twice on the leaves of Yucca.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC0FE24FF16C4FF0FBE881B.taxon	description	This species is commonly found in field as well as in moist chamber cultures.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC0FE24FF16C5330D028AB7.taxon	description	It is scanty material with small, dispersed sporocarps, up to 0.9 mm in total height. Sporotheca cylindric, reddish brown, 0.35 mm width., and 0.75 mm height. The peridium is evanescent. With a stalk that is short, dark, conical, 0.1 mm width., 0.15 mm height, ~ 12.5 % in total height. Columella reaching almost to the sporotheca apex, where it bifurcates into two primary branches. The capillitium with perpendicular primary branches arising along the entire length of the columella, with membranous expansions. The capillitium bifurcates and sometimes anastomoses to form an internal open-mesh net, semi-ridged with numerous free ends and sharps. Spores globose, with prominent warts, 9.3 – 9.6 µm diam. Mapimí specimens are closer to Comatricha longipila, from which it differs by having larger spores (6.5 – 7.0 µm diam. according to the original description by Nannenga-Bremekamp in 1962). Nonetheless, the sharp free ends, dichotomous, as well as the short stalk of our specimens appear typical to C. longipila, this species was originally described in the Netherlands by Nannenga-Bremekamp (1962) and in Mexico it has only been reported in Veracruz (López et al. 1981). If confirmed, this species would be the second record for the Neotropical region (Lado & Wrigley de Basanta 2008).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC0FE24FF16C0430F798DF4.taxon	description	Fig. 27 Loc 5: On Agl leaves, JRM 150, 27 May 2009, (mc, pH = 7.9), JRM 182, 19 September 2008, (mc, pH = 8.1). Loc 8: On Ags caudex, JRM 190, 28 August 2008, (mc, pH = 8.7), JRM 229, 5 January 2009, (mc, pH = 8.1). Loc 17: On Ags decayed, JRM 183, 5 February 2009, (mc, pH = 8.5), JRM 234, 1 October 2008, (mc, pH = 8.2).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC0FE24FF16C09B0D9F8F9F.taxon	description	Fig. 28 Loc 4: On Y sp. leaves, JRM 189, 19 April 2009, (mc, pH = 7.7). Loc 5: On Agl leaves, JRM 113, 08 September 2008, (mc, pH = 7.9), JRM 182, 19 September 2008, (mc, pH = 8.1). Loc 6: On Cyt decayed, JRM 180, 28 August 2008, (mc, pH = 8.3). Loc 13: On Agl leaves, JRM 112, 5 February 2009, (mc, pH = 7.9), JRM 115, 28 August 2008 (mc, pH = 8.4). Loc 14: On Ags leaves, AET 11752, 28 October 2007. Loc 16: On Agl leaves, AET 11846 (sub Lado 18993), 31 October 2007. Loc 20: On Agl leaves, AET 11858, 1 November 2007.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC0FE23FF16C2AF0D52883E.taxon	description	Fig. 29 Loc 2: On Prg bark, JRM 252, 5 January 2009, (mc, pH = 7.2). Loc 5: On Agl leaves, JRM 116, 6 April 2009, (mc, pH = 7.9), JRM 153, 24 December 2008, (mc, pH = 7.9), JRM 188, 25 August 2008, (mc, pH = 7.6). Loc 7: On Eur stem, JRM 231, 19 September 2008, (mc, pH = 7.7), JRM 233, 19 September 2008, (mc, pH = 7.0). Loc 11: On Y sp. leaves, JRM 109, 28 November 2008, (mc, pH = 7.6), JRM 177, 13 January 2009, (mc, pH = 8.4). Loc 13: On Agl leaves, JRM 114, 14 January 2009, (mc, pH = 8.1), JRM 185, 5 February 2009, (mc, pH = 8.1). Loc 17: On Ags leaves, JRM 110, 14 September 2008, (mc, pH = 8.2), JRM 234, 6 May 2009, (mc, pH = 8.2). This species was only obtained in moist chamber culture. According to Novozhilov et al. (2003), D. mexicanum was the most abundant species of the genus in moist chamber culture, as well as the most abundant in Colorado Plateau arid zones.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC7FE23FF16C5FB0DD28B5D.taxon	description	This species is only known from Mexico, exclusively developed on species of Agave (Estrada-Torres et al. 2009, Lizárraga et al. 2015).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC7FE23FF16C6E90F958DE2.taxon	description	Fig. 30 Loc. 2: On Prg bark, JRM 252, 5 January 2009, (mc; pH = 7.2). Loc. 13: On Agl decayed, AET 11694 (MA-Fungi 88114 sub Lado 18841), AET 11696 (MA-Fungi 88116 sub Lado 18843), AET 11698 (MA-Fungi 88117 sub Lado 18845), AET 11699 (MA-Fungi 88118 sub Lado 18846), AET 11700 (MA-Fungi 88119 sub Lado 18847), AET 11702 (MA-Fungi 88120 sub Lado 18849), AET 11704, AET 11705, AET 11708 (MA-Fungi 88121 sub Lado 18855), 28 October 2007. Loc. 14: On Ags decayed, AET 11745 (MA-Fungi 88138 sub Lado 18892), AT 11750, AET 11751, AET 11756 (MA-Fungi 88142 sub Lado 18903), 28 October 2007. Loc. 15: On Y sp. leaves, AET 11719, AET 11734 (MA-Fungi 88134 sub Lado 18881), 28 October 2007. Loc. 19: On Ags decayed, AET 11894 (MA-Fungi 88199 sub Lado 19041), 1 November 2007. Loc. 21: On Agl leaves, AET 11865 (MA-Fungi 88188 sub Lado 19012), AET 11866 (MAFungi 88189 sub Lado 19013), AET 11868, AET 11871 (MA-Fungi 88190 sub Lado 19018), AET 11878, 1 November 2007. This species is only known from Mexico, usually developed on species of Agave (Estrada-Torres et al. 2009). Unlike Didymium mexicanum, D. umbilicatum is common in the field, but not in moist chamber culture. Didymium umbilicatum has been considered a synonym of D. mexicanum (Moreno et al. 2012), but there are clear morphological differences that separate both species such as size, shape and morphology of the spores. There are no genetic or molecular studies that include both species to verify that they are of independent evolutionary lineages. A study on species delimitation is necessary to determine the taxonomic validity of Didyium umbilicatum.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC7FE23FF16C1620F6B8C98.taxon	description	This species was only obtained in moist chamber culture. Didymium vaccinum appeared to be commonly associated with dead inner tissue of succulent plants (Lado et al. 2007 a).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC7FE23FF16C1AF0D538FA3.taxon	description	Fig. 31 Loc 3: On Opr cladodes, JRM 187, 4 October 2008, (mc, pH = 8.0). Loc 8: On Ags leaves, JRM 186, 5 January 2009, (mc, pH = 9.0). This species was commonly associated with the dead inner tissue of succulent plants of the Opuntia genus (Lado et al. 2007 b).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC7FE23FF16C2AB087B8E4B.taxon	description	In semi-arid and arid environments, E. arboreum has been found on Yucca debris (Novozhilov et al. 2003) and various cacti such as Cephalocereus, Ferocactus, and Opuntia (Estrada-Torres et al. 2009).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC6FE22FF16C2100CA58E93.taxon	description	The sporocarps are dispersed to gregarious, yellowish white to slightly pinkish, stalked, 13 – 14 µm diam., 59 – 81 µm height and 1 – 2 µm diam. in the apex, filled with granular matter, mainly toward the base. Columella lenticular to hemispherical, approximately 4 µm diam. Peridium persisting at base like a minute collar. All these characters fit the description given by Whitney (1980). Echinostelium brooksii was found in a single locality, mixed with another Echinostelium species. Before this study, Echinostelium brooksii was only known for Tlaxcala (Rodríguez-Palma et al. 2002).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC5FE21FF16C5140CA58AEF.taxon	description	The genus Gulielmina was recently segregated from Perichaena based on molecular evidence (García-Cunchillos et al. 2022).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC5FE21FF16C79C0D958DCF.taxon	description	Yatsuik et al. (2024) reinstated the genus Heterotrichia based on molecular evidence, reclassifying certain yellow, orange, and pinkish species of Arcyria that are distantly related to the clade containing the type species of Arcyria. One such example is H. insignis, previously cited in Tehuacán-Cuicatlán Valley as Arcyria insignis (Kalchbr. & Cooke) by Estrada-Torres et al. (2009).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC5FE21FF16C1EB0FF58F0B.taxon	description	The absence of peridial plates and non-pink colour spores in Licea nannengae makes it possible to distinguish this species from Licea belmontiana Nann. - Bremek. (Lado & Pando 1997).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC5FE20FF16C33C0C818877.taxon	description	Sporocarps dispersed, stalked with sporotheca globose. Thin stalk, 75 % of total height, very dark, yellowish red at the base. Peridium violaceous brown, evanescent with a well-defined collar at the base of the sporotheca. Columella reaches the middle of the sporotheca, where it branches into two or three main branches. Capillitium rigid, hollow, thin, not anastomosed, reaching from the apex to the columella, with spiny free ends and dichotomous ramifications. Spores 9.6 – 10.4 µm, globose, verrucose with clusters of warts. A species close to Mapimí specimens is M. argentea Nann. - Bremek. & Y. Yamam., which has smaller spores (7 – 8.5 µm) and evanescent peridium (Nannenga-Bremekamp & Yamamoto 1983). If confirmed, this species would be the first record for the Neotropics (Lado & Wrigley de Basanta 2008).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC4FE20FF16C5170F3F8B8F.taxon	description	The specimen agrees well with the original description of M. confusa as the capillitium arises along the entire length of columella dissipating into the main capillitium branches. Peridium early fugaceous but with a well-defined collar at the base of sporotheca. Capillitium rigid, anastomosed slightly toward the base of sporotheca, mostly spiny free ends. Spores globose, 9.5 – 10.5 diam., verrucose, violaceous brown. Mapimí specimen differs from M. confusa in the spore size, 7 – 8.5 diam., in the original description, and in the rather lax capillitium. If confirmed, this species would be the first record for the Neotropics (Lado & Wrigley de Basanta 2008).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC4FE20FF16C6BF08CD8DBB.taxon	description	Sporocarps dispersed, stalked, up to 0.45 mm in total height. Stalk conical, short, 0.16 mm height. Peridium evanescent but with a well-defined collar. Sporotheca oblong, 0.3 × 0.26 mm. Columella almost reaches apex of the sporotheca, where it branches into two or three main branches. Capillitium anastomosed, forming a superficial net, with numerous spiny free ends, which does not correspond with the original description of M. oblonga that has free blunt ends, slightly swollen or club shaped (Pando & Lado 1988). Most of the characters agree with the description of M. oblonga, except by the smaller spores in Mapimí specimens, 7.9 – 9.9 diam., versus (9 –) 10 – 11 µm reported by Pando & Lado (1988). This species has been reported from Colorado Plateau (Novozhilov et al. 2003) and Tehuacán-Cuicatlán Valley (Estrada-Torres et al. 2009).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC4FE20FF16C0D30DBF8F2F.taxon	description	Fig. 32 Loc 11: On Y sp. debris, JRM 126, 12 May 2009, (mc, pH = 7.5), JRM 198, 13 September 2008, (mc, pH = 7.6). This specimen is characterized by the globose, sub-stipitate sporocarps (Fig. 30), 0.9 – 1.2 mm diam., bright yellow, with dehiscence by polygonal plates. The capillitium scanty, with irregular tubular threads, and short spiny at the surface. Spores are globose and verrucose, 10.9 – 12.7 diam. Mapimí specimens appear to be closer to O. pedata (≡ Perichaena pedata) by the kind of dehiscence, capillitium ornamentation and reminiscent stipes, yet the spore size does not coincide with this species (9 – 10 diam.) (Mitchell 2001). If confirmed, this collection would be the second record of O. pedata for Mexico.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFC4FE20FF16C25F0E0A8EFE.taxon	description	Fig. 33 Loc 1: On Ags leaves, 20 August 2008, JRM 120 (mc, pH = 8.3), 4 September 2008, JRM 200 (mc, pH = 8.2). Loc 3: On Agl leaves, AET 11803, 30 October 2007. Loc 7: On Y sp. debris, 11 November 2008, JRM 244 (mc, pH = 7.5). Loc 9: On Ags leaves, AET 11777, 29 October 2007. Loc 14: On Y sp. leaves, 20 May 2009, JRM 199, (mc, pH = 8.8); on Ags leaves, AET 11739, AET 11741 (MAFungi 88137 sub Lado 18888), AET 11764, 28 October 2007. Loc 18: On Agl leaves, AET 11678 (MA-Fungi 88107 sub Lado 18825), AET 11679, 27 October 2007. Loc 21: On Agl leaves, AET 11886, 1 November 2007.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFDAFE3EFF16C4FF09D48BC6.taxon	description	Fig. 34 Loc 3: On Eur stems, JRM 196, 4 September 2008, (mc, pH = 8.0). Loc 4: On Y sp. debris, JRM 118, 14 May 2009, (mc, pH = 7.4). Loc 5: On Opr cladodes, JRM 195, 27 May 2009, (mc, pH = 8.0), JRM 215, 10 September 2008, (mc, pH = 8.0). Loc 7: On Eur stems, JRM 131, 28 November 2008, (mc, pH = 7.8). Loc 13: On Agl leaves, JRM 212, 28 November 2008, (mc, pH = 8.1). Loc 16: On Ags caudex, JRM 210, 16 September 2008, (mc, pH = 8.0), JRM 216, 27 May 2009, (mc, pH = 8.0). Loc 18: On Cyt cladodes, JRM 211, 13 January 2009, (mc, pH = 8.4). Mapimí specimens present a great variation in sporocarp shape and size. They have flattened or pulvinated sporocarps, darker or reddish, dispersed or aggregated in small forms, but always with circumcissile dehiscence (Fig. 32). Globose spores, 10.3 – 14.3 diam., slightly larger than original description. Martin & Alexopoulos (1969) & Nannenga-Bremekamp (1991) reported spores of 9 – 12 µm diam., Lado & Pando (1997) of 10 – 12 µm diam., and Neubert et al. (1993) of 8.5 – 11 diam. The capillitium is rather variable with loop filaments and frequently septate. Perichaena depressa and P. quadrata are considered conspecific by Martin & Alexopoulos (1969) but with SEM it is possible to distinguish both species (Keller & Eliasson 1992). Given the impossibility of reviewing each sample in SEM to differentiate capillitium ornamentation, in this study P. quadrata was considered to be only those specimens of pulvinate sporocarps, aggregated in small forms, 0.3 – 0.5 mm, with capillitium not completely looped and septate.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFDAFE3EFF16C7470E968A93.taxon	description	Fig. 35 Loc 1: On Opr cladodes, JRM 198, 1 September 2008, (mc, pH = 7.9), JRM 209, 8 September 2008, (mc, pH = 8.6). Loc 5: On Opr cladodes, JRM 141, 8 September 2008 (mc, pH = 8.6).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFDAFE3EFF16C7BB0DAE8C07.taxon	description	Fig. 36 Loc 3: On Opr cladodes, JRM 126, 25 August 2008, (mc, pH = 8.0). Loc 13: On Agl leaves, JRM 213, 16 September 2008, (mc, pH = 8.1); on Agl leaves, AET 11691, 28 October 2007. Loc 14: On Ags leaves, AET 11736 (MA-Fungi 88136 sub Lado 18883), AET 11742, 28 October 2007. Loc 15: On Agl stem, AET 11724 (MA-Fungi 88130 sub Lado 18871), AET 11729, 28 October 2007. Loc 17: On Cyl cladodes, JRM 142, 27 May 2009, (mc, pH = 7.3). Loc 20: On Ags leaves, AET 11854 (MA-Fungi 88183 sub Lado 19001), 1 November 2007. Loc 21: On Ags leaves, AET 11877 (MA-Fungi 88193 sub Lado 19024); on Ags leaves AET 11889, AET 11890 (MAFungi 88196 sub Lado 19037), 1 November 2007. See comments under P. depressa.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFDAFE3EFF16C10709D78CF8.taxon	description	Fig. 37 Loc 13: On Agl leaves, JRM 108, 19 April 2009, (mc, pH = 7.9). Loc 8: On Ags leaves, JRM 193, 25 November 2008, (mc, pH = 8.7).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFDAFE3EFF16C19708448EDB.taxon	description	a, b, c Physarum dudlianum T. N. Lakh & K. G. Mukerji. [0, 1] Loc 17: On Cyl cladodes, JRM 223, 19 April 2009, (mc, pH = 7.6). Sporocarps stalked with sporotheca sub-globose to slightly depressed, white, with calcium carbonate scales at the surface. Stalk yellow and translucent at the top, dark and opaque base because of refuse material presence. Capillitium with very large and irregular nodes, non-uniformly distributed, sometimes forming a pseudocolumella, and areas devoid of nodes, with a well-defined net of non-calcareous whitish tubules. Spores globose, 9.5 – 10.8 diam., finely ornamented, almost smooth, sometimes with groups of warts visible only by SEM. The Mapimí specimen on Cylindropuntia cladodes matches the original description by Lakhanpal & Mukerji (1981). However, some Mapimí sporocarps do not show the prominent pseudocolumella characteristic of Physarum dudlianum. This is the first record of the species for America and the Neotropics.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFD9FE3DFF16C54F0FD488C2.taxon	description	Physarum licheniforme was previously known only from Baja California in Mexico (Moreno et al. 2001). Our collection extends the distribution of this species within the country.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFD9FE3DFF16C7D70E0E8D04.taxon	description	Fig. 38 Loc 4: On Y sp. leaves, JRM 235, 24 December 2008, (mc, pH = 7.4), JRM 236, 23 April 2009, (mc, pH = 8.0). Loc 8: On Agl cladodes, JRM 171, 24 October 2008, (mc, pH = 8.7).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFD9FE3DFF16C00B0D958C9B.taxon	description	Fig. 39 Loc 8: On Ags leaves, JRM 173, 26 January 2009, (mc, pH = 7.3). Loc 11: On Y sp. debris, JRM 238, 6 March 2009, (mc, pH = 7.5), JRM 239, 26 March 2009, (mc, pH = 8.4). Loc 12: On Prosopis glandulosa bark, JRM 098, 24 October 2008, (mc, pH = 6.7). Loc 14: On Ags leaves, AET 11742 b, AET 11758, AET 11767 (MA-Fungi 88146 sub Lado 18914), 28 October 2007. Loc 16: On Ags leaves, JRM 172, 25 November 2008, (mc, pH = 8.3), JRM 241, 19 March 2009, (mc, pH = 8.0), JRM 243, 6 April 2009, (mc, pH = 6.3). This is a common species in arid zones, and is frequently found on rosulifolious or rosette-leaved succulent plants (Estrada-Torres et al. 2009).	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFD9FE3DFF16C1B30D058FD6.taxon	description	Physarum spectabile has been observed to be a very common species in other regions, for instance in Tehuacán-Cuicatlán Valley in Mexico (Estrada Torres et al. 2009) and Monte Desert in Argentina (Lado et al. 2011). This species is generally found on species of Copiapoa, Eulychnia, and Opuntia. In the Tehuacán-Cuicatlán Valley, it has been reported on Agave, Myrtillocactus, Neobuxbaumia, Opuntia, and Pachycereus. In this study it was found on cladodes of Opuntia rufida.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
487C87B0FFD9FE3CFF16C3AB0CA28113.taxon	description	pH of substratum The resulting pH values in moist chamber cultures differed among species and ranged from slightly acid to alkaline, except for Echinocereus sp. and caudex debris of Agave scabra, which ranged from neutral to alkaline (Fig. 40). The development pH for all species recorded in Mapimí Reserve was different. Our findings show that the myxomycetes of Mapimí do not grow in the pH extreme values. Based on the data available, myxomycetes species only occurred in an intermediate range of the entire pH range of each substrate (Fig. 40). The highest richness of species was localized in a range of 7.5 to 8.5 (87 % of taxa) (Fig. 41). The highest pH values of myxomycetes development were recorded in A. scabra, Opuntia rufida, and Yucca sp., with values close to 9.0 (Fig. 40), where species such as Didymium wildpretii and Badhamia melanospora were recorded. Contrarily, the lowest pH development values were recorded in Prosopis glandulosa bark with values below 7.0 (Fig. 40). Water holding capacity of the substratum In this study, the availability of water varied across all substrates (Fig. 42). Water holding capacity (WHC) ranged from 74 % of retention in Prosopis glandulosa bark up to 282 % in some samples of Agave scabra caudex (Fig. 42). There was a strong variation between samples of the same substrate. For instance, Euphorbia rossiana samples showed a narrower variability (144 % to 184 %), whereas Agave scabra caudex displayed a broader range of variation (83 % to 282 %). This finding may indicate that the size and structure of the substrates are important in water holding capacity. Our results indicate that the substrates used from Mapimí Reserve can absorb up to three times their water weight, mainly in succulent plant remains (Cactaceae, Agavaceae, and Euphorbiaceae), except Prosopis glandulosa bark. Based on the results, the substrates of Cylindropuntia leptocaulis, C. tunicata, Echinocereus sp., and Opuntia rufida presented WHC values from 94 % up to 236 % (Fig. 42). Nonetheless, C. leptocaulis and C. tunicata presented the lowest WHC values for Cactaceae, 148 ± 27 and 134 ± 27, respectively. These two species of Cylindropuntia have smaller cladodes than Echinocereus stems (166 ± 24) or Opuntia rufida cladodes (185 ± 31). The substrates of rosulifolious plants also are comparable with Cactaceae. Agave lechuguilla had WHC values from 181 ± 26, whereas Agave scabra had values from 183 ± 24, and Yucca 164 ± 32. The lowest WHC values of all substrates were reported in Prosopis glandulosa bark (from 74 % up to 122 %), with an average value of 109 ± 23. Sixty-nine percent of the species developed in substrates with WHC ranged from 140 % to 175 % (Fig. 43). Nonetheless, Agave scabra caudex presented fungus contamination, because the mycelium covered almost all the substrate. This may also have contributed to being among the less productive substrate with lower species richness. During the hydration process of the Euphorbia rossiana samples, the release of exudates was observed in several of them, which turned the supernatant liquid into a dark green colour. In several cultures with E. rossiana there was no evidence for growth or development of myxomycetes, fungi, dipteran larvae or any other organism normally observed in moist chambers. Based on the average water retention values at 6, 18, and 24 hours, a rapid decrease in the substrates water content was observed (Table 3). For example, at 6 hours, the substrates that lost most of the water were Prosopis glandulosa bark, followed by the two species of Cylindropuntia and the caudex debris of Agave scabra. On the contrary, those that retained the highest moisture were Echinocereus sp., Yucca sp., Euphorbia rossiana and the two Agave species. At 18 hours, the substrates with the highest percentage of water retention were Yucca followed by Agave scabra caudex and Prosopis glandulosa bark; the latter two, being the substrate that lost most of the water in the first 6 hours (Table 3). All substrates, except Agave scabra, retained less than 25 % of water. After 24 hours, all substrates had lost nearly all moisture, retaining only between 2 % and 3 % of the water gained during saturation. Only Euphorbia rossiana and Agave scabra caudex retained 6 to 10 % of water. Curiously, these substrates are among the least productive and have the poorest myxobiota species. It should be noted that these data hardly reflect water loss under natural conditions, where substrates are usually piled in large quantities or under the shade of living parts of plants, retaining water for a longer time. However, this parameter serves as a reference point to determine which substrates have a greater capacity to maintain humidity conditions for a longer period of time. When comparing the percentage values of water retained at 6 hours with those reported in other studies, it can be noticed that substrates from the Mapimí Reserve, such as Cylindropuntia species, have similar values to those of lianas (64 ± 11) or to the Neotropical bark trees (65 ± 11), while Prosopis glandulosa bark has moisture retention similar to those of lianas bark (56 ± 17). Nonetheless, all Mapimí Reserve substrates retain a greater quantity of water than those of some cacti bark (26 ± 8) or European trees (26 ± 6), which surely provides them with conditions to support development of myxomycetes in the Mapimí Reserve environmental arid conditions. However, most substrates have practically lost all water within 24 hours, in contrast to some Neotropical tree bark, which retained around 26 ± 20 % moisture.	en	Montes, José Rubén, Lado, Carlos, López-Ortiz, Nelly María, Estrada-Torres, Arturo (2025): Desert Protists unveiled: Myxomycetes (Amoebozoa) diversity in the Mapimí Biosphere Reserve, Chihuahuan Desert’s arid refugia. Phytotaxa 715 (1): 1-31, DOI: 10.11646/phytotaxa.715.1.1, URL: https://doi.org/10.11646/phytotaxa.715.1.1
