Flora of New Zealand Series

Description : Lichenicolous. Colonies delimited, erumpent through the upper cortex of the host thallus, pale-pink or orange-pink; mycelium immersed in the cortex and medulla of host, hyphae flexuose, irregularly branched, hyaline, torulose, often markedly constricted at septa, thin-walled, mainly 2.5–4 μm wide. Conidiophores micronematous, forming sporodochia, densely compacted, very irregular and difficult to distinguish, sporodochia very variable, mainly 200–300 μm wide, applanate to almost coremiiform. Conidiogenous cells probably monoblastic, sometimes evidently polyblastic, integrated, terminal or intercalary, irregular in shape, mainly ellipsoidal to elongate–ellipsoidal, hyaline. Conidia catenate often adhering in compact masses 50–100 μm tall, hyaline singly, but pale-pink in mass, simple, subglobose but often rather angular through compression by adjacent conidia, thin-walled, indistinctly verruculose, rather variable in size, mainly (4–)6–7 μm diam.

N: S: Westland (Haast River), Otago (Teviot Valley, Lake Onslow) St: Throughout.Very common on Peltigera didactyla, occurring as pink or orange-pink aggregated granules on the thallus and soralia (Galloway 1999). Apparently growing quickly in autumn and winter, and becoming visually apparent on the rather weedy, fast-growing host on clay banks, along roadsides etc, at such times. Alstrup & Hawksworth (1990: 38) note that "... Nectriella robergei (Mont. & Desm.) Weese has often been considered to be the teleomorph of this species but this now seems to be extremely dubious...".

Cosmopolitan

Hosts : Apparently restricted to the thalli of species of Peltigera. It is particularly common on P. didactyla in New Zealand, but is known also from P. canina, P. horizontalis, P. malacea, P. polydactylon and P. rufescens in the Northern Hemisphere (Vouaux 1914b: 317; Hawksworth 1979a: 235; Alstrup & Hawksworth 1990; Goward et al. 1994b; Esslinger & Egan 1995; Martínez & Hafellner 1998; Triebel & Scholz 2001; Diederich 2003).

Illustrations : Keissler (1930: 630, figs 131, 132); Hawksworth (1979a: 233, fig. 23; 234, fig. 24); Diederich & Sérusiaux (2000: Frontispiece); Brodo et al. (2001: 7, pl. 5).

* Illosporium carneum is characterised by: the lichenicolous habit; the pale-pink to orange thalli occurring on the upper cortex of Peltigera didactyla.