Amorphomyces ventricosus Santam., 2021

Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, European Journal of Taxonomy 781, pp. 1-425 : 279

Amorphomyces ventricosus Santam. sp. nov.

MB#840594

Fig. 65C–G

Diagnosis

Similar to Amorphomyces falagriae Thaxt. , but the female thalli differ by the bulging on the perithecial margin involving second and, sometimes, also the first wall cells tiers, i.e., w 2 and part of the w 1 cell; and for straight male thalli.

Etymology

The species epithet means “inflated” and refers to the swelling of the perithecial margin.

Type material

Holotype DENMARK – Lolland, Falster, Møn (LFM) • On Myrmecocephalus concinnus (Erichson, 1839) (Col. Staphylinidae Aleocharinae ); Stensø ved Nakskov ; 54°49.465′ N, 11°7.254′ E; PF37; 7 Jan. 2018; JP 951; JP det.; ZMUC C-F-123457 .

Description

Male thalli consisting of a basal cell (I) about 2–3 times as long as broad, hyaline except for the dark brown lower foot; suprabasal cell (II) slightly longer as broad, about half as long as the basal cell, rectangular in section, uniformly darkish brown, separated by an almost horizontal septum from cell I; antheridium flask-shaped, symmetrical, with a venter variably tinged with brown, bearing an elongate, straight, ± brown efferent neck ( Fig. 65G ).

Female thalli yellowish brown except for the darkened foot and lower part of cell I; basal cell (I) as long as broad, enlarged distally, separated by an oblique septum from cells above; perithecium asymmetric, largely fusiform, slightly bent, with a smoothly curved margin on one side and with a conspicuous bulging of a w 2 cell above and also a slightly inflated w 1 cell on the opposite side; the perithecial tip slightly asymmetric, rounded, blunt, showing a centered apical ostiole.

Length of male thalli from foot to apex of antheridium 57–62 µm. Venter of antheridium 12–13 × 7–8 µm. Length of efferent neck 13–19 µm. Length of female thalli from foot to apex of perithecium 157–190 µm. Perithecium (length from septum above cell I × width at bulging) 144–167 × 39–41 µm.

Thalli were found on abdominal tergites of the host. The host was sifted from mouldy, warm fermenting wood chips.

Remarks

This species should be compared with A. falagriae but is easily distinguished from it by the swelling of the perithecium below the middle of the margin. The genus host of A. ventricosus sp. nov. is known as Falagrioma Casey, 1906 or Falagria Leach, 1819 in old literature, the latter is the host for A. falagriae . The new species is the only of the genus showing a bulging on the perithecium margin, only remotely comparable with A. biformis Thaxt. which shows an unusual lateral finger-like extension. Amorphomyces ventricosus sp. nov. doesn’t show a free primary appendage.

Figures

Fig. 65. A–B. Tavaresiella hebri T.Majewski. Two mature thalli with labelled I, II, III cells, elongated main cell of inner appendage branch (*), and darkened projection from cell I (arrows). – C–G. Amorphomyces ventricosus Santam. sp. nov. C. Lower area of perithecium in detail to focus on cells n and some of the wall cells (w n). D–F. Female mature thalli. G. Male thallus with labelled cells I, II and antheridium (an). Scale bars: A–B, D–F = 50 µm; C, G = 25 µm. Photographs from slides ZMUC C-F-124090 (A–B), ZMUC C-F-123457 (D–G) (holotype).