Flora of New Zealand Series

≡Lecidea phaeostoma Nyl. in J. Crombie, J. Bot. 13: 334 (1875).

Description : Thallus dingy white, irregularly areolate, often poorly developed, K+ yellowish. Prothallus usually indistinct. Apothecia to 2 mm diam., usually much smaller (0.3–0.8 mm), frequent, sessile, with a ±thin, black, prominent, often crenulate margin; disc ±flat, rust-coloured K+ red (2-chloroemodin), resembling a species of Caloplaca, reddish pruina sometimes absent in old or damaged apothecia, but usually conspicuous in younger fruits. Exciple and hypothecium very dark, almost black, ±confluent, K+ dark red-brown. Hymenium 55–80 μm high, paraphyses simple, conglutinated; epithecium dark-green (rarely pale- or olive-green) overlain by a thin yellow-orange pruina (tomato-red in K). Ascospores ellipsoidal, 7–15 × 4.5–8.5 μm. Conidia filiform, often curved, 14–20 × 1 μm.

Chemistry : Atranorin, zeorin (thallus), 2-chloroemodin (pruina of apothecia) (Hertel 1985b).

S: Otago (Kaka Point, Jacks Bay), Southland (Bluff, Howell's Point, Cosy Nook). A: C: On coastal rocks occurring with Lecanora austrooceanica and Tephromela atra (Hertel 1990). Associating also with Caloplaca circumlutosa, C. sublobulata, Placopsis cribellans, Pertusaria graphica and Rinodina thiomela. A circum-Antarctic species known also from Macquarie I., Kerguelen, Heard I., Marion I. and Prince Edward Is and the Falkland Is (Hertel 1984a, 1984b, 1985b, 1987b, 1989b, 2001; Øvstedal & Gremmen 2001; McCarthy 2003c, 2006).

Austral

Exsiccati : Hertel (1984a: 1).

Carbonea phaeostoma is characterised by: the saxicolous habit (coastal rocks); the rust-red pruinose discs (K+ red) of the young apothecia. Hertel (1989b: 213) raised doubts as to the correct placing of this species in Carbonea, but hesitated to include it either in Lecanora or Adelolecia.