Stigmatodiscus pinicola

Stigmatodiscus pinicola Voglmayr & Pintos, Mycol. Progress 17(10): 1195. 2018.

MycoBank MB827489

AUTHORS: Pintos A. & Voglmayr H.
Taxonomic classification

phy Ascomycota

sbp Pezizomycotina

cls Dothideomycetes

sbc

ord Stigmatodiscales

fam Stigmatodiscaceae

gen Stigmatodiscus

sp Stigmatodiscus labiatus

 

Description

Ascomata hysteriform to apothecioid, scattered, corticolous, initially covered by bark, erumpent through the periderm, in face view (205–)255–410(–600) μm long, (145–)180–285(–375)μm wide (n=30), with sides consisting of usually 2–3 black lips (peridium) not in mutual contact, with a slit-like to circular central opening exposing the blackish elongated to circular disc. Bark tissues not visibly altered, no black line visible in bark or wood. Peridium coriaceous, pseudoparenchymatous, dark brown, up to 70 μm thickat the apex, 15–25 μm thick at the sides, almost absent to 20(–30) μm thick at the base, composed of small angular to rounded brown cells 3–9 μm diam. Hamathecium composed of hyaline, septate, filiform branched paraphyses 1.5–3.5 μm wide, embedded in tough hymenial gel, simple, not anastomosing, ca.150–220μm long, longer than asci, swollen at their apices up to 7 μm and incrusted with dark brown granules forming an epithecium, neither staining blue in Lugol nor in Melzer’s reagent after pre-treatment with 3% KOH. Asci (104–)111– 135(–138)×47–54(–57) μm ( n=10), bitunicate, broadly fusiform to ellipsoid, almost sessile, with a distinct apical chamber, thick-walled, typically containing 8 irregularly bi- to triseriate ascospores, very stable, fissitunicate dehiscence not observed. Ascospores (40.5–)43.5–50(–52.5)×(13.5–)14.5– 16.8(–18.0) μm, l/w=(2.6–)2.8–3.2(–3.5) (n=45), brown, asymmetric, fusiform, straight, first 1-septate, developing 2 additionaldistoseptaandbecoming3-septatewithage,strongly constricted at the primary septum, weakly at secondary septa, secondary septa with large pores, each hemispore surrounded by a separate gelatinous sheath, upper hemispore slightly broader, with subacute to rounded ends, end cells lighter brown at maturity; wall finely verruculose, brown, the contents granular, often with a large and several smaller guttules per cell.

Conidiomata on the natural substrate associated with ascomata, visible as minute black dots 110–200 μm in diam, immersed, peridermal, pycnidial, clypeate, unilocular, of circular shape,opening with a central ostiole,140–230μmdiam, 130–210 μm high, marginal wall ca. 14–25μm thick, of light brown cells, wall around ostiole ca. 30–60 μm thick, composed of brown cells. Ostiole dark brown, ca. 20–25μm wide. Conidiophores short, branched up to two times. Condiogenous cells phialidic, cylindrical, (9.5–)12.0–17.2(–21.2)×(1.9–)2.2–2.9(–3.0) μm( n=30). Conidia (18–)19– 25(–28)×1–1.6 μm( n=30), hyaline, falcate to semicircular, aseptate.

 

References in our territory

 

Specimens in scientific collections

* sequenced material

Reference specimen marked in bold

Mll: AP21916B*.

 

Sequences in public databases obtained from material collected in our territory

AP21916B: MH756073 (SSU), MH7560673 (ITS-LSU), MH756076 (RPB2), MH756093 (tub2)

 

Erumpent ascomata (AP21916B, holotype). Scale= 1 mm. Photograph: H. Voglmayr.

Ascoma (AP21916B, holotipo). Scale= 1 mm. Photograph: H. Voglmayr.

Ascoma section (AP21916B, holotype). Scale= 100 µm. Photograph: H. Voglmayr.

 

Ascoma (AP21916B, holotype). Scale= 20 µm. Photograph: H. Voglmayr.

Paraphyses in KOH (AP21916B, holotype). Scale= 10 µm. Photograph: H. Voglmayr.

Ascóspora (AP21916B, holotipo). Escala= 10 µm. Foto: H. Voglmayr.

Ascospore (AP21916B, holotype). Scale= 10 µm. Photograph: H. Voglmayr.

Conidioma section (AP21916B, holotype). Scale= 20 µm. Photograph: H. Voglmayr.

Conidiophore (AP21916B, holotype). Scale= 10 µm. Photograph: H. Voglmayr.

Conidium (AP21916B, holotype). Scale= 10 µm. Photograph: H. Voglmayr.

How to cite this sheet:

Pintos A. & Voglmayr H. 2020. Stigmatodiscus pinicola Voglmayr & Pintos. Fichas SIM (updated on 17-V-2020)