Jahnula purpurea J. Fourn., Raja & Shearer

Fournier, Jacques, Raja, Huzefa A. & Shearer, Carol A., 2015, Freshwater Ascomycetes: Jahnulapurpurea (Jahnulales, Dothideomycetes), a new species on submerged wood from Martinique Island, Lesser Antilles, MycoKeys 9, pp. 29-36 : 29-31

Taxon classification Fungi Jahnulales Aliquandostipitaceae

Jahnula purpurea J. Fourn., Raja & Shearer sp. nov. Figs 1, 2

Holotype.

FWI, Martinique: Prêcheur, Anse Couleuvre, Couleuvre River, coastal rainforest, 14°50'13.05"N, 61°13'22.40"W, on submerged decorticated branch, 03 Jun. 2014, J. Fournier, MJF 14016; (ILLS 72402).

Description.

Ascomata 125-185 (-220) µm diam, globose to subglobose, scattered or clustered in small groups, immersed-erumpent, the base remaining immersed in the substrate, brownish black appearing black when dry, attached to subtending golden brown hyphae 8-22 µm diam, smooth, slightly constricted at septa; hyphae form cords developing under the wood surface and linking adjacent ascomata (Fig. 1 A–D); wood beneath ascomata or at the periphery of the colony stained purple; ostiole non-papillate, slightly depressed, pallid, rounded, minute, filled with hyaline periphyses (Fig. 1F). Peridium appearing roughened by protruding cells (Fig. 1B, D), 22-35 µm wide, two-layered: outermost layer textura angularis, composed of 1-2 rows of large thick-walled cells 8-18 µm in their greatest dimension, extending into hyphal appendages in places (Fig. 1F), more pigmented in upper half, inwardly lined by smaller hyaline flattened cells forming a textura prismatica (Fig. 1E, F). Asci 90-98 × 22.5-25 µm, bitunicate, with fissitunicate dehiscence occurring rarely, clavate to slightly obclavate, shortly pedicellate, 4-8-spored, ascospores 1-3 seriate (Fig. 2 G–I); apex without (Fig. 2J) or with a faint truncate ocular chamber (Fig. 2K). Pseudoparaphyses 1-2.5 µm wide, cellular, often contorted, sparsely septate, rarely anastomosing, embedded in a gel matrix (Fig. 2G, L). Ascospores (23) 24-28 (31) × (7) 8-9 µm, (mean = 26 × 8 µm; n = 60), ellipsoid-fusiform, 1-septate, septum median to slightly submedian (0.53, N = 20), slightly constricted at the septum, upper cell wider and often apically pinched, lower cell obtusely rounded (Fig. 2H, I, M), contents densely guttulate; wall medium brown, minutely verrucose with warts partially in contact and forming a loose reticulate pattern (Fig. 2N), visible in hyaline immature ascospores; no sheath or appendages observed in aqueous nigrosin or India ink (Fig. 2O).

Etymology.

From Latin “purpureus” referring to the characteristic staining of the substrate purple by this species.

Anamorph.

Not known.

Known distribution.

Martinique, Lesser Antilles (Known only from type locality thus far).