Lambiella parvipsephota Kantvilas, 2022

Kantvilas, Gintaras, 2022, The genus Lambiella Hertel (lichenised fungi) in Tasmania: new combinations, new species and a revised key, Phytotaxa 549 (2), pp. 209-218 : 213-214

Lambiella parvipsephota Kantvilas , sp. nov. Mycobank no. 844104

( Figs 1A, 1B )

Similar to Lambiella psephota (Tuck.) Hertel and L. subpsephota (Fryday) Fryday , from which it differs by a combination of a thallus containing norstictic acid, the absence of sedifolia -grey pigment in the apothecia, relatively small apothecia, 0.1−0.2 mm wide, and small ascospores, 8−13 × 5–7.5 µm.

Type:— AUSTRALIA. Tasmania, Cockle Bay Lagoon, 42°42’S 147°56’E, 1 m elevation, on dolerite cobbles along the sea shore, well above the high tide mark, 24 July 2011, G . Kantvilas 221/11 (holotype − HO) .

Thallus crustose, areolate, dull pale grey, matt, closely adnate to the substratum, forming rather neat, roundish patches to 50 mm wide, delimited by a thin, grey-black prothallus; areoles 0.1–0.5 mm wide, to c. 150−200 µm thick, mostly convex, roundish to rather angular, contiguous, delimited by deep fissures; cortex poorly differentiated, to 10 µm thick; medulla patchily I+ violet, KI+ violet; photobiont a unicellular green alga ( Chlorella - type) with cells irregularly globose to rhomboid, 5–13 × 5−11 µm, with a gelatinous sheath c. 1 µm thick. Apothecia 0.1−0.2 mm wide, lecideine, roundish to deformed-elongate or ± angular, especially when squashed together, adnate and nestled between the thallus areoles; disc black, plane, minutely roughened but not gyrose; proper exciple black, persistent, entire, elevated a little above the level of the disc, in section cupulate, opaque brown, K+ reddish brown, 15–40 mm thick laterally, mostly thicker basally, composed of rather cellular hyphae 4−6 µm wide. Hypothecium 30−40 µm thick, hyaline, I−. Hymenium 55−60 µm thick, mostly hyaline, KI+ intense blue, brownish, K± intensifying reddish brown in the upper part; paraphyses richly branched and anastomosing, 1.5−2 mm wide, with apices unpigmented, occasionally moniliform and expanded to 3 µm; asci 8-spored, broadly clavate, 38–50 × 17–26 µm, approximating the Trapelia - type, with an intensely amyloid wall, a well-developed tholus, amyloid at the flanks and apex but non-amyloid elsewhere and lacking any internal differentiation. Ascospores simple, persistently hyaline, non-halonate, thin-walled, oblong to ellipsoid, rarely subglobose, (8−)9– 10.4 –12(−13) × 5– 6.0 –7–7.5) µm (n = 55). Conidiomata not seen.

Chemistry: norstictic and connorstictic acids, detected by TLC and under the microscope, where squashes of the thallus and apothecia produce red, needle-shaped crystals upon the addition of K.

Etymology: the specific epithet alludes to the smaller apothecia and ascospores of the new species in comparison to L. psephota .

Notes: With its dull grey, areolate thallus containing norstictic acid, this species, on first inspection, resembles L. psephota , a widespread and common saxicolous lichen in Tasmania, and was intially though to be a diminutive variant of that species. Although mainly found on exposed rocks in alpine, high mountain environments, L. psephota is also known from lower pinnacles, where its occurrence is interpreted as relict from a past colder, drier climate. However, to consider that L. psephota might also occur on sea-shore cobblestones seemed an incredible extension of its ecological niche and initiated further study.

Lambiella parvispsephota differs from L. psephota by several morphological and antomical characters. The latter has larger apothecia (to 0.9 mm diam.), larger ascospores (12−21 × 6.5−13 µm) and contains sedifolia -grey pigment (greenish brown, K+violet, C+ violet) in the epihymenium (see Kantvilas 2014). The asci of the two species are also slightly different, with those of the new species having essentially Trapelia - type asci, whereas those of L. psephota display signs of a highly reduced apical ring-structure in the tholus (see Kantvilas 2014: Fig. 4E). Furthermore, whereas the ascospores of L. psephota tend to turn brown with age, those of the new species remain hyaline throughout development. Also somewhat similar is L. subpsephota (Fryday) Fryday , described from Tierra del Fuego and the Falkland Island ( Fryday & Øvstedal 2012). Interestingly, this species also occurs on maritime rocks, but differs from the new species by lacking norstictic acid, containing sedifolia -grey, and having somewhat longer, broader ascospores (13−15 × 9−10 µm) ( Fryday & Øvstedal 2012). The new species was also compared to the Northern Hemisphere’s L. impavida (Th.Fr.) M.Westb. & Resl but that species is essentially a coarser lichen with bigger areoles, an I− medulla, usually contains stictic acid, and has marginally smaller ascospores (5.5−10 × 6−8 µm) ( Hertel & Rambold 1990).

Lambiella parvipsephota is known from a single locality on Tasmania’s east coast. It was collected from dolerite cobbles along the sea-shore, just above the high tide mark in a zone where an incipient hinterland lichen community is developing. Associated lichens here include Candelariella vitellina (Hoffm.) Müll.Arg. , Lecanora galactiniza Nyl. , Lecidella sublapicida (C.Knight) Hertel , Rhizocarpon geographicum (L.) DC., Rinodia thiomela (Nyl.) Müll.Arg. , Tephromela atra (Huds.) Hafellner and Xanthoparmelia mougeotina (Nyl.) D.J.Galloway. The new species was found sporadically only in this narrow band, and neither in the immediate hinterland nor in the littoral zone dominated by Caloplaca species and Tylothallia verrucosa (Müll.Arg.) Kantvilas.

Additional specimen examined. type locality, 4 August 2013, G . Kantvilas 191/13 (HO).

Figures

FIGURE 1. New Tasmanian Lambiella species. A. L. parvipsephota habit, showing rimose-areolate thallus on a black prothallus (scale = 1 mm) and detail of thallus areoles and apothecia (inset, scale = 500 µm). B−C. Asci and ascospores with amyloid parts after pretreatment in K stippled: L. parvipsephota (B) and L. plumbea (C). Scale = 10 µm.