A NEW SPECIES OF HEMITRICHIA IN SUCCULENT PLANTS * G. MORENO, A. CASTILLO, A. LÓPEZ-VILLALBA & A. SÁNCHEZ Dpto. de Ciencias de la Vida (Botánica), Edificio de Biología, Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain Correspondence to *:
[email protected] Summary. MORENO, G., A. CASTILLO, A. LÓPEZ-VILLALBA & A. SÁNCHEZ. (2017). A new species of Hemitrichia in succulent plants. Bol. Soc. Micol. Madrid 41: 31–35. Hemitrichia succulenticola is described as a new species to science based on abundant material collected on remains of Opuntia spp. from Spain and Mexico. This new species can be distinguished from other members of the genus by brown to orange brown globose sporocarps, a capillitium network of tubular threads with few free ends and big warty spores. Images of diagnostic morphological features are provided. Key words: Amoebozoa, myxobiota, slime moulds, taxonomy. Resumen. Una nueva especie de Hemitrichia de plantas suculentas. Bol. Soc. Micol. Madrid 41: 31–35. Se describe Hemitrichia succulenticola como una nueva especie para la ciencia basada en abundante material recogido en restos de cladodios de Opuntia spp. de España y México. Esta nueva especie se diferencia de otros miembros del género por sus esporocarpos pardos a pardo anaranjados, el capilicio formado por una red de filamentos tubulares con pocas terminaciones libres y las esporas grandes y verrugosas. Se proporcionan imágenes de sus características morfológicas. Palabras clave: Amoebozoa, myxobiota, hongos mucilaginosos, taxonomía.
INTRODUCTION The genus Hemitrichia Rostaf. (Trichiaceae, Trichiales) includes at present 26 species (LADO, 2005-2017) and is widely represented in Spain. The genus comprises species with both plasmodiocarps and sporocarps. It is characterized by the presence of tubular branched threads in the capillitium, forming an elastic net with few free ends. This feature differentiates the genus Hemitrichia from the genus Trichia Haller, which has an elateriform capillitium with tubular, elastic, free and simple threads, rarely branched, and with many free ends. Bol. Soc. Micol. Madrid 41. 2017
This paper describes a Hemitrichia species that has been misinterpreted by different authors (LADO, 1993; LADO & PANDO, 1997; LIZÁRRAGA & al., 1999; MORENO & al., 2000; LIZÁRRAGA & al., 2004, SÁNCHEZ & MORENO, 2016) and confused with Hemitrichia minor. The new species is apparently very frequent in xeric areas, where Opuntia spp. grows. MATERIALS & METHODS We studied samples from Mexico (Baja California) and Spain (Almería, Badajoz, Cádiz, Gran 31
G. MORENO, A. CASTILLO, A. LÓPEZ-VILLALBA & A. SÁNCHEZ
Canaria, Segovia and Tenerife). The new species has been introduced in the Mediterranean region with Opuntia spp. plantations. The material studied is preserved in the herbarium AH (Plant Biology herbarium of the University of Alcalá, Madrid; Spain). Slide mounts in Hoyer’s medium for each specimen are preserved in AH. Spore measure ments were made using an oil immersion objective and included such surface structures as warts and spines. Scanning electron microscopy (SEM) micrographs were obtained at the University of Alcalá using a Zeiss DSM-950 instrument. Sporocarps were rehydrated in concentrated ammonium hydroxide (28-30%) for 30 minutes, dehydrated in aqueous ethanol (70%) for 30 minutes, fixed for two hours in pure ethylene glycol dimethyl ether (= 1,2-dimethoxymethane) and finally immersed in pure acetone for at least two hours followed by critical point drying and sputtering with goldpalladium. This technique allows the use of very little material (part of a single sporocarp or no more than a few spores). DESCRIPTION Hemitrichia succulenticola G. Moreno, A. Castillo, López-Villalba & A. Sánchez, sp. nov. = H. minor G. Lister, sensu auct. pluribus non G. Lister Etymology. Succulenticola (from Latin succulentus = fleshy and cola = dweller) refers to the habitat on which it grows (succulent plants). Typus. Spain, Cádiz, Alcalá de los Gazules, on cladodes of Opuntia ficus indica, 14-XI-1992, G. Moreno & A. Ortega, AH 16114 holotype, MycoBank MB 820097. Additional specimens examined. Mexico, Baja California, Ensenada, Las Chichiuas, on cladodes of Opuntia ficus indica, 1-II-1996, M. Lizárraga, AH 20080. Spain, Almería, Los Retacos, road from Tabernas to Turrillas, on cladodes of Opuntia ficus indica, 25-II-1994, G. Moreno, A. Altés & C. Illana, AH 16651; Almería, dry riverbed from Tabernas to Turrillas, 16-II-1997, G. Moreno, A. Altés, C. Illana, J. Checa & M.N. Blanco, AH 45734. Badajoz, Azuaga, “Finca La Jacoba”, on cladodes of Opuntia ficus indica,
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Fig. 1.- Spain, characteristic vegetation where the holotype was collected.
3-X-1990, J. R. García, AH 13031; idem, 6-III-1992, idem, AH 16118; idem, AH 16127; idem, AH 16169; idem, 10-XI1992, AH 16170; idem, 23-XI-1993, AH 16304, isoparatype in BPI. Cádiz, Alcalá de los Gazules, on cladodes of Opuntia ficus indica, 14-XI-1992, G. Moreno & A. Ortega, AH 15496; idem, AH 16100; idem, AH 16110; idem, AH 16115. Gran Canaria, Barranco de Guayadeque, 20-XII-1979, on cladodes of Opuntia ficus indica, G. Moreno & C. Lado, AH 47012; idem, AH 47012; idem, AH 47013; idem, AH 47014; idem, AH 47015; idem, AH 47016. Segovia, Monte La Viña, Segovia capital, on cladodes of Opuntia sp., 15XII-2003, AH 26451. Tenerife, Vilaflor near Pino Gordo, 28º 9’ 54’’ N, 16º 38’ 11” W, 2006 m, on cladodes of Opuntia ficus indica, 30-IV-2016, A. Sánchez, A. López-Villalba, L. Monje & G. Moreno, AH 46140; idem, AH 46141.
Sporocarps scattered or clustered, globose to subglobose (0.4–0.8 mm in diam) or short plasmodiocarps (up to 1.5 mm in length), brown to orange brown, sessile or rarely with a very short Bol. Soc. Micol. Madrid 41. 2017
A NEW SPECIES OF HEMITRICHIA IN SUCCULENT PLANTS
Fig. 2- Hemitrichia succulenticola G. Moreno, A. Castillo, López-Villalba & A. Sánchez holotype AH 16114, a–b. Sporocarps, c. Detail of capillitium, d. Free ends of capillitium, e–g. Capillitium with globular to oval widening, h. Spores. i. Detail of capillitium, j. Free ends of capillitium, k–l. Capillitium with globular to oval widening, m. Inner surface of peridium, n. Spore, o. Details of the spore ornamentation. Scale bars: a–b = 0.5 cm, c–h = 10 µm, i–l = 5 µm, m = 2 µm, n = 2 µm, o = 1 µm.
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blackish brown stalk. Hypothallus inconspicuous. Peridium double, with two layers that keep together, persistent, fragile, membranous; under SEM inner surface striate and papillate. Irregular dehiscence. Capillitium and spores in mass orange yellow. Capillitium formed by a network of tubular threads, elastic, yellow to olivaceous brown, paler in transmitted light, tubules 2–3 µm in diam., flexuous, branched, tangled, with globular to oval widenings and few short and sharp free ends. The tubular filaments are ornamented with 3–4 prominent and irregular spirals and pronounced and abundant spines clearly visible under SEM. Spores globose to subglobose, 12–15.2 × (11–)12–14.4(–14.8) µm in diam., av. 12.6–14.1 × 12–13.5 μm, Qav = 1.04–1.06, pale yellow in transmitted light, warted. Under SEM spore ornamentation is formed by pila with irregular distribution. Habitat and distribution: This is a succulenticolous species occurring isolated or gregarious. It is apparently very frequent in areas with Opuntia spp. DISCUSSION Hemitrichia succulenticola is characterized by its brown to orange brown globose sporocarps, its capillitium consisting of anastomosed tubules with spiral bands and globular to oval expansions and few free ends, its (sub)globose spores (12.6–14.1 × 12–13.5 µm on average), and by growing on succulent plants. Hemitrichia succulenticola is macroscopically similar to Perichaena corticalis. But the latter species has a quite different capillitium, with pored, irregular branches with neither spirals nor spines (MORENO & al., 2000). Perichaena corticalis usually grows on bark of deciduous ripa rian trees, such as Populus and Betula. Hemitrichia succulenticola could be confused with Trichia agaves, which also grows on succulent plants, but the latter species shows a tesselate peridium, not papillated on the inner surface, the capillitium has faint spirals bands, scarce spines and it lacks the typical swellings shown by the proposed new species (MORENO & al., 2000). 34
Hemitrichia minor differs from the proposed new species by its minute pale yellowish-buff sporocarps (0.2–0.4 mm diam.), smaller spores (9–10 µm in diam.), and growth on bark of dead and living trees, moss and dead leaves (LISTER, 1911, 1925). The capillitium of H. minor consists of a loose network of flaccid yellow threads, which shows bulbous expansions also present in Hemitichia succulenticola. This feature has been the reason of misinterpretation of this latter species by different authors (LADO & PANDO, 1997; LIZÁRRAGA & al., 1999; MORENO & al., 2000; LIZÁRRAGA & al., 2004). ACKNOWLEDGMENTS We wish to express our gratitude to Dr. Harald Singer for revision of the manuscript. We thank Dr. L. Monje and Mr. A. Pueblas of the Department of Drawing and Scientific Photography at the University of Alcalá for their help in the di gital preparation of the photographs. We thanks Mr. A. Priego and Mr. J.A. Pérez of the Electron Microscopy Service of the University of Alcalá for their invaluable help with the SEM. Thanks are extended to Dr. J. Rejos, curator of the AH herbarium for his assistance with the specimens examined in the present study. BIBLIOGRAPHY LADO, C. (1993). Cuadernos de trabajo de Flora Micológica Ibérica 7. Bases corológicas de la Flora Micológica Ibérica. Números 376-692. C.S.I.C. Real Jardín Botánico. 305 págs. LADO, C. (2005-2017). An on line nomenclatural information system of Eumycetozoa. Real Jardín Botánico, CSIC. Madrid, Spain. http:// www.nomen.eumycetozoa.com (22-3-2017). LADO, C. & P. PANDO (1997). Myxomycetes, I. Ceratiomyxales, Echinosteliales, Liceales, Trichiales. Flora Mycologica Iberica 2: 1323. LISTER, G. (1911). Two new species of Mycetozoa. J. Bot. 49: 61–62. LISTER, A. & G. LISTER (1925). A monograph of the Mycetozoa. A descriptive catalogue of the species in the Herbarium of the British Bol. Soc. Micol. Madrid 41. 2017
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Museum. Oxford University Press 222 p. LIZÁRRAGA, M., C. ILLANA & G. MORENO (1999). SEM studies of the Myxomycetes from the Peninsula of Baja California (Mexico), II. Hemitrichia to Trichia. Ann. Bot. Fenn. 36: 187–210. LIZÁRRAGA, M., G. MORENO & C. ILLANA (2004). Contribución al estudio de los Myxomycetes de la Península de Baja California, Méxi-
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co. Bol. Soc. Micol. Madrid 22: 43–54. MORENO, G., M. LIZÁRRAGA, C. ILLANA, A. CASTILLO & M. OLTRA (2000). Hemitrichia agaves sp. nov. un nuovo Myxomycetes delle piante grasse dal Messico e dalla Spagna. Rivista Micol. 43(1): 5–16. SÁNCHEZ, A. & G. MORENO (2016). Catálogo de Myxomycetes de Segovia. Bol. Soc. Micol. Madrid 40: 37–68.
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