Lepidopterella tangerina Raja & Shearer
Holotype: ILL 40112
Etymology: From Latin tangerinus = orange, referring to the orange ascospores.
Sexual morph: Ascomata on wood 120–190 × 230–300 µm, cleistothecial, scattered to gregarious, superficial to partially immersed, globose to subglobose, appearing as raised dome-shaped structures on the substrate. Peridium 8–10 µm wide, textura angularis in surface view, in median longitudinal section composed of an outer dark brown amorphous layer and an inner hyaline region of 2–3 layers of elongated, thin-walled, angular cells. Pseudoparaphyses sparse, hyaline, septate, not covered in gel. Asci 78–130 × 40–58 µm, ( = 106 × 50 µm, n = 20), produced successively on ascogenous hyphae, then separating from the ascogenous hyphae, globose to subglobose, thick-walled and broadly rounded at the apex, with a short pedicel, containing eight irregularly arranged ascospores, fissitunicate, ectoascus rupturing at the apex to release the endoascus; endoascus extending to ca. 90–150 µm long; cytoplasm of discharging endoascus finely granular, with granules delimiting spheres. Ascospores 16–19 µm long at the septum and 30–35 µm wide at the broadest point ( = 18 × 32 µm, n = 40), papilionaceous to broadly reniform, 1-septate, bi- to multi-guttulate, orange to light orange-brown, smooth-walled. Asexual morph: undetermined. (Description from Raja and Shearer 2008)
Material examined: USA, Florida, Blackwater River State Forest, Blackwater River, north end, at Kennedy Bridge, 30°56′01″N, 86°44′07″W, water 11 C, pH 5, on submerged corticated woody debris, 11 Feb 2006, HAR and JLC, F118-1. (HOLOTYPE ILL40112).
Notes: The characteristics of L. tangerina fit within the concept of the genus Lepidopterella (Shearer and Crane 1980). Lepidopterella tangerina however differs from the type of the genus, L. palustris Shearer & J.L. Crane, in ascospore morphology and size. The ascospores of L. tangerina are broadly reniform and shorter at the midseptum (17–19 µm) compared to the ascospores of L. palustris, which are deeply constricted in proportion to the overall spore morphology (butterfly shaped) and consistently longer at the midseptum (18–25 µm) (Shearer and Crane 1980). The midseptum of the ascospore is darkened in L. palustris but not in L. tangerina. In addition, mature ascospores of L. palustris are darker than those of L. tangerina. (Notes from Raja and Shearer 2008)
Freshwater distribution: USA (Raja and Shearer 2008; Raja et al. 2009)
Fig. 1. Lepidopterella tangerina (ILL40112, holotype) 71. Cleistothecial ascoma on wood. 72. Longitudinal section through an ascoma. 73. Two layered peridium. 74. Cellular pseudoparaphyses. 75. Ascus with a short pedicel. 76. Asci developing successively from the ascogenous hyphae. 77. Fissitunicate ascus, note granular cytoplasm of endoascus with granules delimiting spheres. 78–80. Mature multiguttulate ascospores. Bars: 71 = 500 µm, 72 = 50 µm, 73–80 = 20 µm. (from Raja and Shearer 2008)
Raja HA, Schmit JP, Shearer CA (2009) Latitudinal, habitat and substrate distribution patterns of freshwater ascomycetes in the Florida Peninsula. Biodivers Conserv 18:419–455. https://doi.org/10.1007/s10531-008-9500-7
Raja HA, Shearer CA (2008) Freshwater ascomycetes: new and noteworthy species from aquatic habitats in Florida. Mycologia 100:467–489. https://doi.org/10.3852/07-167R
Shearer CA, Crane JL (1980) Taxonomy of two cleistothecial ascomycetes with papilionaceous ascospores. Trans Br Mycol Soc 75:193–200. https://doi.org/10.1016/s0007-1536(80)80079-9