Cruentotrema lirelliforme J. Kalb, Polyiam & K. Kalb, 2016

Polyiam, Jutarat Kalb Wetchasart, Plata, Eimy Rivas, Bawingan, Paulina A., Kalb, Klaus & Lücking, Robert, 2016, ‘ Missing links’ alive? Novel taxa represent morphological transitions between distinctive phenotypes among extant Graphidaceae (lichenized Ascomycota: Ostropales), Phytotaxa 268 (2), pp. 110-122 : 115

Cruentotrema lirelliforme J. Kalb, Polyiam & K. Kalb , sp. nov. ( Fig. 2B–D )

MycoBank MB817435

Differing from Cruentotrema thailandicum in the lirelliform ascomata.

Type: ― THAILAND. Nakon Ratchasima : Khao Yai National Park, about 100 m on road from training center to Haoo Suwat waterfall ; 04º44’ N, 73º50’ W, 3600 m; tropical rain forest, on bark; 20 October 2002, W. Polyiam 21520 (holotype RAMK) .

Thallus corticolous, epiperidermal, grey-olive, smooth to uneven, with dense, prosoplectenchymatous cortex; photobiont layer with scattered clusters of calcium oxalate crystals. Apothecia erumpent, angular to elongate-lirellate, 1–3(–5) mm long and 0.7–1 mm broad; disc immersed, thinly white-pruinose but hidden by a splitting thallus layer that exposes a deep red-pigmented medulla (easily mistaken for representing the disc); margin formed by the outer portions of the thallus layer, erect to fissured, partly flaking off, grey-olive, inner parts red-pruinose. Excipulum prosoplectenchymatous, dark brown or upper half carbonized. Periphysoids absent. Columella absent. Hymenium 90–100 μm high; paraphyses unbranched. Ascospores 8/ascus, 3-septate, 20–30 × 7–10 μm, ellipsoid, with thick septa and diamond-shaped lumina ( Astrothelium - type), colorless, I– (non-amyloid).

Secondary chemistry: —Medulla of apothecial margin with dark red, K+ yellowish green pigment (isohypocrelline).

Etymology: ―The epithet refers to the peculiar morphology of the ascomata.

Distribution and ecology: ― Thailand; thus far only known from the type locality, growing on bark of trees in the rain forest understory.

Remarks: ―This new species has the typical features of Cruentotrema species, i.e. the red medullary pigment in the ascomata, the ascomata opening by rupturing into irregular lobules, and the I-negative, Astrothelium - type ascospores, but differs clearly in the lirelliform ascomata. It provides a morphological transition towards Dyplolabia , but is also reminescent of certain species of Acanthothecis with partially exposed, reddish disc, such as A. mirabilis Staiger & Kalb (1999: 107) , A. rosea (Vain.) Staiger & Kalb in Staiger (2002: 81), and A. sanguinoloba (Redinger) Staiger & Kalb (1999: 110) , as well as Fissurina species with partially exposed disc and lobulate margins, although red pigments are absent in that genus ( Staiger 2002). Acanthothecis is phylogenetically unrelated and differs by the spinulose paraphyses and the thin ascospore septa, as well as the lack of carbonization. Fissurina , on the other hand, is a polyphyletic agglomerate, with several lineages more closely related to Cruentotrema and Dyplolabia .

Figures

FIGURE 2. A. Enigmotrema rubrum (holotype; thallus with ascomata). B–D. Cruentotrema lirelliforme (holotype; thallus with ascomata and ascospores). E–F. C. thailandicum (holotype; thallus with ascomata). Scale = 1 mm, in D = 10 μm.