Flora of New Zealand Series

≡Platygrapha occulta C.Knight & Mitt., Trans. Linn. Soc. 23: 104 (1860).

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

≡Schismatomma occultum var. microstictum (C.Knight & Mitt.) Zahlbr., Cat. lich. univ. 2 (4): 560 (1923).

=Platygrapha constricta Kremp., Verhandl. zool.-bot. Ges. Wien 26: 459 (1876).

≡Schismatomma constricta (Kremp.) Zahlbr., Cat. lich. univ. 2 (4): 555 (1923).

=Platygrapha occulta f. evolutior Nyl., Lich. Nov. Zel.: 119 (1888).

=Platygrapha occulta f. decolorascens Nyl., Lich. Nov. Zel.: 119 (1888).

Lectotype: New Zealand. Auckland, sine loco, 1858. Charles Knight 267/a – BM [fide Galloway (1985a: 522)]. Isolectotype – M, ? WELT.

Platygrapha microsticta. Lectotype: New Zealand. Auckland, sine loco, 1858, Charles Knight 203 – BM [fide (Tehler 1993: 11)]. Isolectotype – ?WELT.

Platygrapha occulta f. evolutior. Holotype: New Zealand. Sine loco [probably Wellington], 1867, Dr Knight 54, sub "Platygrapha microsticta" – H-NYL 4744.

Platygrapha occulta f. decolorascens. Holotype: New Zealand. Sine loco [probably Wellington], 1867, Dr Knight 51a – H-NYL 4745.

Descriptions : Flora (1985: 521). See also Tehler (1993c: 12–13).

Chemistry : Cortex K−, C−, KC−, Pd−; containing roccellic acid.

N: Auckland, Wellington – known only from type collections. On smooth bark. Known also from New South Wales (Tehler 1993c: 12) and a single collection from Tasmania (Kantvilas 2004j: 201–202.)

Australasian

Illustrations : Knight & Mitten (1860: pl. XII, fig. 26 – as Platygrapha occulta; pl. XII, fig. 23 – as P. microsticta); Tehler (1993c: 11, fig. 2); Kantvilas (2004j: 201, fig. 9).

Schismatomma occultum is characterised by: the corticolous habit; the coherent, brownish to cream-brown thallus; erumpent, elongate to lirelliform or stellate ascomata, that are immersed to subsessile; epruinose discs; a dark-brown, carbonised hypothecium; and subsigmoid to straight or slightly curved ascospores, 33–38 × 2–3 μm. It is similar to Chiodecton colensoi, but this latter species differs in several respects, mainly in the perithecioid to pseudomonocarpocentral ascomata, the K+ red thallus reaction (secalonic acid), the filiform semicircular microconidia, the longer ascospores, and the nearly smooth epithecial hyphae tips (Thor 1990).