Lithothelium kiritea
Family
Pyrenulaceae
Flora category
Lichen – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Lichens - Crustose
Interim conservation status
2024 | Not Threatened | Qualifiers: DPS, DPT | Interim | Marshall et al (2024)
Brief description
White crustose lichen covering the trunks of exposed cabbage tree (Cordyline australis) growing in coastal and lowland sites. Thallus white, with numerous large, prominent, black fruitingf bodies.
Distribution
Endemic: New Zealand - North Island (Auckland, Northland, Te Aupouri, Te Paki), also Tairawhiti (near Gisborne); South Island, North Westland; Chatham Islands, Rēkohu / Wharekauri / Chatham Island.
Habitat
So far Lithothelium kiritea has only been recorded from the bark of Cordyline australis trees growing in open / exposed conditions (Marshall et al. 2024). The species seems to be a mainly lowland, narrowly coastal species which rarely extending inland for more than a few kilometres. It has an altitudinal range of 1-270 m a.s.l.
Detailed description
Corticolous on Cordyline australis. Thallus white to pale buff, appearing whiter with age, darker when fresh and often appearing darker around perithecia, without marginal prothallus. Angular crystals present throughout, fleck-like, 60−150 × 30−60 μm. Photobiont — green (genus not evident, probably Trentepohlia). Perithecia — simple, without pseudostromatic tissues. Conical to globose, usually erumpent from substratum but very occasionally partially covered, 0.8−1.0 mm diam., 0.5−0.8 mm tall, usually 0.15−0.30 mm emergent from thallus. Ascocarp wall completely carbonised, without distinct clypeus, 35–50 μm thick. Ostiole black, rimmed, rim paler than ascocarp, 150−350 μm diameter, usually apical but occasionally skewed. Hamathecium — inspersed with oil droplets, IKI–, paraphyses simple, not branched at tips, approx. 1 μm thick. Asci — fissitunicate with rounded ocular chamber, tending to slightly sagittiform at maturity, 160−225 × 20−25 μm. Ascospores — 4−8/ascus, uniseriate, colourless at first but becoming red-brown with age. Lumina tending towards angular with rounded corners, 3-septate, central two lumina larger than the terminal lumina, 32−40 × 12−15 μm. Spore wall smooth, without granules. Pycnidia — not always present, 240−450 μm diameter, black, wall completely carbonised; spermatia acrogenous, filiform, colourless, curved 15−20 × 0.25−0.50 μm.
Chemistry. UV negative, no substances detected with TLC.
Similar taxa
Lithothelium australe is a basicolous, saxicolous (rather than corticolous) species of limestone rocks that is so far believed endemic to the Chatham Islands. This species has grey to dark grey green-tinged rather than a white to pale buff thallus typical of Lithothelium kiritea when fresh, and L. australe has ascospores measuring 20−26 × 6−8 µm rather than 32−40 × 12−15 μm.
Threats
Lithothelium kiritea is usually an abundant, at times locally dominant lichen of the trunks of Cordyline australis in coastal locations. Currently it is known from a small of New Zealand though abundant in that area (Marshall et al. 2024). It should be looked for elsewhere as this species is more likely overlooked than truly absent, though indications are that it is a ‘recent’ arrival from overseas, probably Australia - and it should be looked for over there as well (Marshall et al. 2024). Currently the species has a provisional assessment of ‘Not Threatened’ (Marshall et al. 2024).
Etymology
kiritea: From te reo Māori [Māori language] meaning ‘white skinned’ in reference to the white covering the species applies to the bark of its host phorophyte.
Attribution
Fact sheet prepared by Peter J. de Lange (19 June 2024) based on Marshall et al. (2024)l
References and further reading
Marshall A.J., Aptroot A., Blanchon D.J., James C.J., de Lange P.J. 2024. New Zealand Lithothelium (Pyrenulaceae) — description of a new species Lithothelium kiritea sp. nov., with notes on L. australe. Ukrainian Botanical Journal 81(2): 145–154. https://doi.org/10.15407/ukrbotj81.02.145
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Lithothelium kiritea Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/lithothelium-kiritea/ (Date website was queried)