ISSN (print) 0093-4666 © 2012. Mycotaxon, Ltd. ISSN (online) 2154-8889 MYCOTAXON http://dx.doi.org/10.5248/120.437 Volume 120, pp. 437–441 April–June 2012 First record of the sequestrate fungus Neosecotium macrosporum (Agaricales, Lepiotaceae) from Mexico Marcos Lizárraga 1 , Martín Esqueda 2* , Mario Vargas-Luna 1 & Gabriel Moreno 3 1 Dpto. de Ciencias Químico-Biológicas, Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Anillo Envolvente Pronaf y Estocolmo s/n, Cd. Juárez, Chihuahua 32300, México 2 Centro de Investigación en Alimentación y Desarrollo, A.C. Apartado Postal 1735, Hermosillo, Sonora 83000, México 3 Dpto. de Biología Vegetal, Facultad de Biología, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain * Correspondence to: esqueda@ciad.mx Abstract — Neosecotium macrosporum, previously known only from two USA records, is reported for the first time in Mexico. Observations of macro- and microscopic characters including for the holotype and the Chihuahua collection are presented. SEM photomicrographs illustrating spore ornamentation are included. Key words — Basidiomycota, taxonomy, hypogeous fungi, secotiaceous fungi Introduction Sequestrate fungi are considered a polyphyletic group with no evolutionary relationships whose morphological similarity comes from the adaptation to extreme habitats and environmental conditions (Albee-Scott 2007). he approximately 1200 species are distributed among eleven orders representing the phyla Zygomycota, Ascomycota, and Basidiomycota. Distinguishing characteristics are a fleshy, cartilaginous or elastic fruiting body with a persistent peridium that encloses the spore producing tissue and thus prevents the easy release of the spores (Kendrick 1992). Most sequestrates are mycorrhizogenic and serve as a source of food for a number of mammals (Trappe & Claridge 2003). here are few studies of this group in Mexico. he first sequestrate fungus recorded for Mexico was collected by Lumholtz (1902) and later designated as the holotype of Melanogaster umbriniglebus Trappe & Guzmán. Trappe &