Fuscoderma limbatum
Family
Pannariaceae
Flora category
Lichen – Native
Structural class
Lichens - Foliose
Current conservation status
2018 | At Risk – Naturally Uncommon | Qualifiers: DP, SO
Distribution
North Island: South Auckland (Slipper Island, Hauhungaroa Range). South Island: Westland (Stillwater), Canterbury (Boyle River nr Lewis Pass), Otago (Chinaman’s Flat, Dart Valley, Routeburn, Dunedin, Botanic Gardens).
Known also from Tasmania where it is rare.
Habitat
Corticolous, s.l. to 650 m. A characteristic but very widely scattered, lowland forest species most often found among bryophytes and other lichens in moderate to deep shade at or near forest margins, or from trees and shrubs in frost-flat clearings, rarely in urban environments. It is a rather rare epiphyte of Coprosma, Dacrycarpus, Leptospermum scoparium agg., Fuscospora cliffortioides and on a willow trunk by the Leith Stream in shady crevices of moist, old, spongy bark.
Detailed description
Thallus squamulose–subfoliose, irregularly spreading, rosette-forming, congested to ±flat, 0.5–2.5(–4) cm diam. Lobes short, broadly laciniate subcanaliculate in central parts to ± plane or convex, 1–4 mm wide, thick, coriaceous, tough. Margins slightly thickened and curled under at lobe apices, rounded, entire or shallowly notched–incised to occasionally minutely lobulate, often ±wavy, ascending to strongly involute, developing prominent blue-grey to brownish, limbiform soralia on the upturned lower surface, often eroding and leaving large whitish areas at margins of lower surface; soredia coarsely granular to minutely coralloid or glomerulate, 0.1 mm diam. or less, rarely becoming small-lobulate. Upper surface dark blue-green when wet, pale-grey to glaucous chestnut-brown when dry, matt to shining, shallowly papillate centrally, distinctly areolate–scabrid at margins and occasionally silky white-tomentose at lobe apices. Lower surface white to cream or pale-buff, delicately arachnoid, without rhizohyphae. Apothecia and pycnidia not seen.
Chemistry: Medulla P+ yellow-orange; containing vicanicin and norvicanicin.
Similar taxa
Specimens of Fuscoderma limbatum show little variation and are often found as scattered and rather few individuals among other lichens. Superficially it appears to be a slightly more leafy, sorediate version of F. applanatum but it has a different chemistry. It is distinct from Leioderma sorediatum which has an arachnoid upper surface, and no chemistry.
Substrate
Corticolous
Attribution
Fact sheet prepared by Marley Ford (5 January 2022). Brief description, Distribution, Habitat, Features and Similar taxa sections copied from Galloway (2007).
References and further reading
Galloway D.J. 2007: Flora of New Zealand: Lichens, including lichen-forming and lichenicolous fungi. 2nd edition. Lincoln, Manaaki Whenua Press. 2261 pp.