typification

Holotype: NEW ZEALAND. Chatham Islands, Rēkohu | Wharekauri | Chatham Island, Southern Tablelands, track to Lake Rangatapu, Waipurua Valley Headwaters, –44.107560, –176.599290, 259 m a.s.l., P.J. de Lange CH4647 & D. Boyle, 26 December 2025. Abundant on Hymenophyllum demissum (G. Forst.) Sw. growing on forest floor, on logs, rocks and on the lower trunks of trees in dense tarahinau (Dracophyllum arboreum Cockayne), mataire (Myrsine chathamica F. Muell.) with karamu hikoa (Coprosma chathamica Cockayne) and hoho (Pseudopanax chathamicus Kirk) forest. [iNaturalist NZ Species Identification Number: 332319696 (https://www.inaturalist.org/observations/332319696)]. UNITEC15158, isotype AK

James, D.J.; Blanchon, D.J.; de Lange, P.J. 2026: A revision of the Coenogonium luteum (Coenogoniaceae) complex in Aotearoa | New Zealand, with new records and new species, and a note on C. tomentosum. Ukrainian Botanical Journal 83(2): 73–86. (Published online: 30 April 2026)

editorial

Mycobank accession number: 863462

James, D.J.; Blanchon, D.J.; de Lange, P.J. 2026: A revision of the Coenogonium luteum (Coenogoniaceae) complex in Aotearoa | New Zealand, with new records and new species, and a note on C. tomentosum. Ukrainian Botanical Journal 83(2): 73–86. (Published online: 30 April 2026)

Etymology

The epithet “goniocystosum” refers to the distinctive thallus of this species, consisting of goniocysts that become obvious when hydrated and observed under a microscope.

James, D.J.; Blanchon, D.J.; de Lange, P.J. 2026: A revision of the Coenogonium luteum (Coenogoniaceae) complex in Aotearoa | New Zealand, with new records and new species, and a note on C. tomentosum. Ukrainian Botanical Journal 83(2): 73–86. (Published online: 30 April 2026)