Flora of New Zealand Series

≡Thelotrema muscigena Stizenb., Jahrsb. St. Gall. Naturwiwss. Ges. 1888–89: 247 (1890).

=Topeliopsis muscicola Kantvilas & Vězda, Lichenologist 32 (4): 348 (2000).

Description : Thallus crustose, whitish grey to grey-green, effuse, not delimited, continuous, ±patchy or lacking. Apothecia adnate or partially immersed, 0.25–0.5(–0.7) mm diam., subglobose to barrel-shaped at first, with excipulum completely closed, becoming "perithecioid" with a ragged, central, ostiole-like opening, 0.08–0.12(–0.3) mm diam., finally "gyalectoid" at maturity. Exciple pale-pink to orange-brown at first, becoming radially fissured, scurfy, exfoliating, thickly white-pruinose in upper part, ±smooth and orange-brown in lower parts adjacent to thallus, 30–80 μm thick, hyaline to pale-brown, cupular and extending below hymenium, internally I+ purple-blue; periphyses abundant at upper inner edge, to 25 μm long and 2 μm thick; disc completely enclosed at first, then ±totally exposed, persistently urceolate, dark grey-brown, becoming eroded with age. Hypothecium hyaline, 12–40 μm thick. Medulla below hymenium I+ purple-blue. Hymenium 160–300 μm tall, colourless, without any epithecium but sometimes orange-brown in upper parts; paraphyses simple, straight to somewhat flexuous, 1–1.5 μm thick, apices not swollen. Asci cylindrical, monosporous, 180–220 × 35–50 μm, at first with a thickened apex, but at maturity entirely filled by the developing ascospore, rupturing readily. Ascospores hyaline to pale greyish, broadly ellipsoidal, muriform, I+ purple, with thin septa and numerous component cells 2–5 μm wide, 105–200(–270) × 25–50(–60) μm.

Chemistry : TLC−, all reactions negative.

N: Northland (Te Paki), South Auckland (Hunua Ra.). S: Nelson (Springs Junction), Canterbury (Nina Valley, Boyle River Lodge). Overgrowing bryophytes on bark or rocks in humid, shaded Nothofagus forest habitats. It is known also from Tasmania (Kantvilas & Vězda 2000: 350; McCarthy 2003c, 2006) and from Table Mountain, South Africa (Kalb: 2001a: 322).

?Austral

Illustration : Kantvilas & Vězda (2000: 349, fig. 9).

Exsiccati : Vězda (2001: No. 459).

Topeliopsis muscigena is characterised by: the muscicolous habit; its mature, gyalectoid apothecia with a scurfy-eroded, whitish margin, grey disc, and very large, muriform ascospores. The ascospores are easily extruded from the asci and may be seen as greyish, cylindrical structures, rather like invertebrate frass, lying free on the disc, on the apothecial margins or on the thallus (×10 lens).