Flora of New Zealand Series

≡Leucodecton colensoi A.Massal., Bull. Soc. Nat. Moscou 36: 266 (1863).

=Platygrapha inconspicua C.Knight & Mitt., Trans. Linn. Soc. 23: 103 (1860).

≡Chiodecton inconspicuum (C.Knight & Mitt.) C.Knight, Trans. N. Z. Inst. 8: 321 (1876) non Nyl. [Acta Soc. Sci. fenn. 7: 486 (1863)].

=Platygrapha tumidula C.Knight & Mitt., Trans. Linn. Soc. 23: 103 (1860).

≡Platygraphis tumidula (C.Knight & Mitt.) Hook.f., Handb. N. Z. Fl. 2: 558 (1867).

≡Schismatomma tumidula (C.Knight & Mitt.) Zahlbr., Cat. lich. univ. 2 (4): 565 (1923).

=Chiodecton conchyliatum Stirt., Bot. J. Linn. Soc. 14: 471 (1875).

=Chiodecton moniliatum Stirt., Bot. J. Linn. Soc. 14: 472 (1875). Chiodecton submoniliforme Nyl., Lich. Nov. Zel.: 117 (1888) pro syn.

=Chiodecton sinuosum Stirt., Bot. J. Linn. Soc. 14: 472 (1875).

=Stigmatidium subtilissimum Nyl., Lich. Nov. Zel.: 118 (1888). [For typifications and additional synonymy see Thor (1990: 34–35).]

Holotype: New Zealand. Sine loco. Colenso ex Herb. Babington – VER. Isotype – BM.

Platygrapha inconspicua. Lectotype: New Zealand. Auckland, 1858. Charles Knight 286 – BM [fide Galloway (1985a: 92)].

Platygrapha tumidula. Lectotype: New Zealand. Auckland, sine loco, 1858, Charles Knight 287 – BM [fide Galloway (1985a: 522)].

Chiodecton conchyliatum. Lectotype: New Zealand. Near Wellington, J.Buchanan 121 – GLAM [fide Galloway (1985a: 91)]. Isolectotypes – BM, WELT.

Chiodecton moniliatum. Lectotype: New Zealand. Near Wellington, J.Buchanan – BM [fide Galloway (1985a: 92)].

Chiodecton sinuosum. Lectotype: New Zealand. Near Wellington. J. Buchanan – BM [fide Galloway (1985a: 92)]. Isolectotype – BM.

Stigmatidium subtilissimum. Lectotype: New Zealand. Sine loco [probably Wellington], 1867, C. Knight – H-NYL [fide Thor (1990: 34)]. Isolectotype – WELT. [Incorrectly cited as a synonym of Schismatomma tumidulum by Galloway (1985a: 521).]

Descriptions : Flora (1985: 91); Thor (1990: 35–36).

Chemistry : Roccellic acid and yellow pigments (secalonic acid derivatives [Thor 1990: 35]).

N: Northland (Kaitaia, Mt Auckland near Glorit, Waiwera Scenic Reserve). Auckland (Waitakere Ra.), Wellington (Mt Ruapehu, Wellington). S: Nelson (Tasman Mts, Roding Valley), Marlborough (Branch R.), Canterbury (Banks Peninsula), Otago (Mt Cargill). On bark of Agathis australis, Dacrydium cupressinum, Phyllocladus and other forest trees, s.l. to 980 m. Widely distributed also in Australia from Queensland to Tasmania (Thor 1990; Kantvilas 1990c; Kantvilas & Thor 1993; McCarthy 2003c, 2006). On rimu scales it forms often quite extensive colonies, together with other Roccellaceous taxa such as Bactrospora arthonioides, B. metabola, and species of Lecanactis.

Australasian

Illustrations : Knight & Mitten (1860: pl. XII, fig. 24 – as Platygrapha inconspicua; pl. XII, fig. 25 – as Platygrapha tumidula); Massalongo (1863: pl. III); Knight (1876: pl. 10, fig. 15; 1877: pl. XXXVIII, fig. 5 – as Chiodecton (Platygrapha) inconspicua); Nylander (1888: tab. 1, fig. 8 – as Stigmatidium subtilissimum); Thor (1990: 34, fig. 18, 36, fig. 20B); Kantvilas & Thor (1993: 39, pl. 1); Malcolm & Malcolm (2000: 133); Lumbsch et al. (2001: 41).

Chiodecton colensoi is characterised by: the corticolous habit, the clustered, perithecioid to lirelliform, black apothecia aggregated in stroma-like structures with 1–10 apothecia per stroma; a hymenium without oil droplets or granules; branched, prominent, paraphyses with pale-brown, K+ olive-grey apices; yellow pigments in the lower part of the medulla; and narrowly fusiform, curved, 3-septate ascospores, 35–55 × 3–4 μm.