Quasiconcha

The genus Quasiconcha Barr & Blackwell
Mycologia 72: 1224. 1980

by Eric W.A. Boehm 

The genus Quasiconcha was established by Barr & Blackwell (1980) to accommodate Q. reticulata M.E. Barr & M. Blackw., an unusual mytilinidioid fungus, with 1-septate, highly reticulated ascospores, borne in conchate, thin-walled ascomata, found in association with Juniperus seeds excreted in dung and the roots of two conifers from the southwestern United States (Barr & Blackwell 1980; Blackwell & Gilbertson 1985). In the present study, we were fortunate to obtain original material (RLG 141189) of Q. reticulata (Boehm et al. 2009b) from Meredith Blackwell (Louisiana State University, Baton Rouge, LA), from which we isolated DNA (EB QR). Sequence data (Fig. 1 Boehm et al. 2009b) clearly indicate that the genus Quasiconcha belongs to the Mytilinidiaceae, in close association with Lophium, to which its fruitbodies most closely resemble.

Barr (1990): “Ascomata superficial, scattered, conchate, medium sized; apex cristate, opening by longitudinal slit; surface black, shining, somewhat longitudinally striate; peridium carbonaceous, brittle, composed of radiating rows of parallel cells, heavily pigmented. Asci cylindric. Ascospores brown, ellipsoid, symmetric, straight one septate median constricted; wall coarsely reticulate, surrounded by delicate outer coating when immature; homogeneous; uniseriate in the ascus. Anamorph in culture as thick-walled chlamydospores & enteroblastic phialoconidia (Blackwell & Gilbertson, 1985). On ovules of Juniperus in animal dung; conifer roots. Type & sole species: Q. reticulata Barr & Blackwell. Type: on ovules of Juniperus virginiana in dung of ring-tailed cat, Hamilton’s Pool, Travis Co., Texas, 32 Jan 1967, M. Blackwell NY! (holotype). Ascomata 495 – 1000 μm long, 385 – 550 μm high, up to 300 μm wide. Asci 45 – 55 x 6 – 7.5 μm. Ascosproes 6 – 8 x 5 – 5.5 μm. Distribution: On ovules & roots of gymnosperms, southern United States. The ascospores have a striking resemblance to those of Testudina terrestris Bizzozero, a cleistothecioid fungus known from fallen conifer twigs & leaves in Europe. Blackwell & Gilbertson (1985) reported Q. reticulata from conifer roots (Pinus halpensis, Thuja occidentalis) in Arizona. They were successful in germinating ascospores & described & illustrated the formation of thick walled halydospores & enteroblastic phialoconidia in culture”.

Quasiconcha reticulata Barr & Blackwell, Mycologia 72: 1224. 1980.