{{Short description|Species of lichen}} {{Use dmy dates|date=October 2025}} {{Use New Zealand English|date=October 2025}} {{Speciesbox | image = | image_caption = | taxon = Verrucaria adguttata | authority = Zahlbr. (1941) }}

'''''Verrucaria adguttata''''' is a species of crustose lichen in the family Verrucariaceae.<ref name="CoL_5B7T2"/> It was first discovered growing on coastal rocks at Rangitoto Island near Auckland, where it tolerates the harsh conditions of salt spray and tidal influence. The species is be endemic to New Zealand's offshore islands.

==Taxonomy==

''Verrucaria adguttata'' was formally described as a new species in 1941 by the German lichenologist Alexander Zahlbruckner. The type was collected by the New Zealand botanist Harry Allan.<ref name="Zahlbruckner 1941"/>

==Description==

The thallus (lichen body) grows on rock and forms scattered, rounded patches that are tightly adherent to the surface. Patches are very thin, smooth, and up to about 10&nbsp;mm across, with slightly undulating margins. The colour is dark brown to nearly black and almost opaque; when wetted the surface becomes faintly gelatinous. No distinct {{lichengloss|hypothallus}} (a border around the thallus) is present. The {{lichengloss|cortex}} is thin and brownish, made of densely interwoven fungal hyphae. The photosynthetic partner consists of bright-green, spherical algal cells 8–10&nbsp;μm in diameter, arranged more or less in vertical series. Standard spot tests are negative (K−, C−).<ref name="Zahlbruckner 1941"/>

Fruiting bodies (perithecia) are small, {{lichengloss|sessile}}, and glossy black, to about 0.25&nbsp;mm in diameter, sitting free on the thallus and typically convex, with the pore only slightly depressed. The pale {{lichengloss|exciple}} (perithecial wall) is capped by a sooty, hemispherical {{lichengloss|involucrellum}} that is closely appressed almost to the base; it does not flare outwards and is truncate beneath. The internal tissue is colourless with confluent paraphyses; an iodine stain gives wine red to yellowish tones. Asci are plentiful, club-shaped, 8-spored, measuring to about 40 × 9–10 micrometres (μm). Spores are hyaline (colourless), {{lichengloss|simple}} (non-septate), straight, narrowly oblong-cylindrical with rounded ends, 9–11.5 × about 3&nbsp;μm, generally arranged in two rows within the ascus. Asexual propagules are produced in small, half-immersed pycnidia with a shiny black top, 60–65&nbsp;μm in diameter and a relatively wide pore. The conidia are very short, rod-shaped, straight to nearly straight, 2–3&nbsp;μm long.<ref name="Zahlbruckner 1941"/>

==Habitat and distribution==

The type material was collected on stone at the edge of a salt lagoon on Rangitoto Island, Auckland. The species occupies hard coastal substrates in the supralittoral zone influenced by salt spray and periodic wetting.<ref name="Zahlbruckner 1941"/> The lichen has also been recorded from similar habitats near Egeria Rock on Raoul Island.<ref name="de Lange 2014"/>

==See also== * List of ''Verrucaria'' species

==References== {{Reflist|refs=

<ref name="CoL_5B7T2">{{Catalogue of Life |id=5B7T2 |title=''Verrucaria adguttata'' Zahlbr. |access-date=17 October 2025}}</ref>

<ref name="de Lange 2014">{{cite journal |last=de Lange |first=Peter J. |year=2014 |title=The flora of Egeria rock, northern Kermadec Island group |journal=Wellington Botanical Society Bulletin |volume=55 |pages=41–49 |url=https://bts.nzpcn.org.nz/site/assets/files/23418/wbs_2014_bulletin_55-complete_41-49.pdf}}</ref>

<ref name="Zahlbruckner 1941">{{cite journal |last=Zahlbruckner |first=A. |year=1941 |title=Lichenes Novae-Zelandiae a cl H. H. Allan eiusque collaboratoribus lecti |trans-title=Lichens of New Zealand collected by the distinguished H. H. Allan and his collaborators |journal=Denkschriften der Akademie der Wissenschaften (Wien) Mathematisch-naturwissenschaftliche Klasse |volume=104 |pages=249–380 [250] |language=la}}</ref>

}}

{{Taxonbar|from=Q49617388}}

adguttata Category:Lichen species Category:Lichens described in 1941 Category:Lichens of New Zealand Category:Taxa named by Alexander Zahlbruckner