Helotiales » Chlorociboriaceae » Chlorociboria

Chlorociboria glauca

Chlorociboria glauca (Dennis) Baral & Pärtel, IF: 815443
Basionym: Encoelia glauca Dennis, Kew Bulletin 30(2): 350 (Dennis 1975), holotype K!
Apothecia cupulate to saucer-shaped, (0.7–)1–2.5(−5.5) mm in diam., receptacle comparatively thin (150–300 μm); scattered or usually gregarious, often 2–5 apothecia growing in clusters, ± deformed by mutual proximity, singly or arising from a ± common base, erumpent from small holes in the periderm, opening in the prohymenial phase; flesh fragile, non-gelatinous; outside pale grey, sometimes with glaucous hue or dirty white, pruinose to pustulate; disc sometimes wrinkled similar to Disciotis venosa, whitish to pale yellowish greyish(−glaucous) or beige, mustard-coloured when dry; with a 0.3–0.8 mm long and 0.5–1 mm wide stipe. Ectal excipulum 40–60 μm at lower flanks, 25–30 μm at upper flanks, of indistinctly vertical t. angularis-globulosa, cells *6–12 × 5–7 μm, ± thin-walled (†thick-walled), hyaline, with light yellowish-ochraceous cloddy intercellular exudate towards medulla cells gradually turning paler light yellowbrown. Hairs hyaline, smooth, protruding, at the margin subcylindrical, flexuous, branching, up to 35–54 × 1.4–2.2 μm, at the flanks up to 8–18 × 2–4(−5) μm, refractive and thick-walled, hyphoid, causing the pruinose appearance of fruitbodies. Medullary excipulum 40–60 μm thick, of dense or loose, to pale avellaneous t. intricata, hyphae *1.5–3.5 μm wide, ± parallel to apothecial surface, thin-walled, with ± scattered, very pale yellowish granular exudate. Subhymenium indistinctly delimited, of a thin, hyaline, dense t. intricata. Asci cylindric-clavate, *38–55 × 4.7–5.6 μm {2}, †31–42 × 3.8–5.3 μm {2}, spores (*) obliquely biseriate, pars sporifera *14–19 μm long, apex (*/†) subconical, apical ring pale blue in IKI and MLZ (without KOH-pretreatment), euamyloid, more distinctly blue in living asci, of ‘Calycina-type’, not liberating spores in water mount even when adding IKI, arising from croziers {4} (rarely with small perforation). Ascospores narrowly subcylindrical, straight to suballantoid, aseptate, with 2–3(−4) small guttules (LBs) near each end, hyaline, *5.5–7.5(−8.5) × 1.5–1.7 μm {2}, †(4–)5–7 × 1.3–1.5 μm {1}. Paraphyses cylindrical to slightly moniliform, straight or slightly flexuous, hyaline, sometimes branched in the middle, sometimes firm-walled in the lower part, terminal cell *22–38 × 2.2–2.7 μm, †1.7–2.1 μm wide, not exceeding the living asci and only slightly the dead asci, lower cells *10–18 × 1.5–2(−2.5) μm; containing non-refractive hyaline vacuoles and a few small LBs; pale (olivaceous-)yellowish granular to cloddy resinous exudate present among and above the hymenial elements, staining bright turquoise-blue in CRB, completely dissolving in KOH (like the exudate in the excipulum) by extruding a very weak pale yellow pigment in the medium (indistinctly ionomidotic). Crystals are absent. Anamorph (observed only on natural substrate in H.B.9236): forming remote, ± gregarious groups of pycnidia on the same branch with the teleomorph, deep greyish-greenish (glaucous), ± globose with a conical tip, densely aggregated to confluent, 0.15–0.3 mm diam., unilocular, peridial cells of t. prismatica-intricata with abundant yellowish-brownish exudate, on the margin forming straight, hyaline, apically tapered (0.9 μm), aseptate hairs 20–30 × 1.4–1.7 μm. Conidiophores arranged in a hymenium, multi-branched (verticillate),
conidiogneous cells phialidic, hyaline, subcylindric, *15–20 × 1.5–2 μm, without collarette. Conidia subcylindrical, straight to very slightly allantoid, hyaline, *3.7–5(−5.3) × (1–)1.1–1.3(−1.4) μm, containing 1(−2) small LBs near each end.
Habitat: on corticated, partly xeric (0–30 cm above ground) branches of deciduous trees and shrubs (Corylus avellana, Prunus spinosa, Salix sp., Rosa sp., canes of Rubus fruticosus). Phenology: Sep. – Dec.
Distribution: rare in Europe (Spain, France, United Kingdom).
Comments. In characterising E. glauca, Dennis (1975) commented on its similarity with "Chlorosplenium" (= Chlorociboria) based on its greenish colour, but he placed it in Encoelia because of the allantoid spores, despite its friable apothecial texture. Asci and ascospores in the holotype as given by Dennis (1975, 40 × 4 μmand 5 × 1 μm, respectively) concur well with the measurements that we observed in other specimens of this species when compared in the dead state. In the holotype in K only juvenile asci and no free ascospores were observed. By the rather small and narrow, subcylindrical, suballantoid ascospores, C. glauca resembles C. aeruginascens (Nyl.) Kanouse and the recently described bryicolous C. lamellicola Huhtinen & Döbbeler (Huhtinen et al. 2010). In other characters C. glauca is more similar to some species described by Johnston and Park (2005) from New Zealand rather than to the few holarctic lignicolous species of Chlorociboria recently revised by Tudor et al. (2014). Specifically, the non-aerugineous, yellowish-glaucous-grey apothecia are reminiscent of some New Zealand taxa, such as C. albohymenia, C. clavula and C. poutoensis. Chlorociboria glauca possesses several unique characters in the genus. It differs from all other species, except C. lamellicola, by not producing a blue-green stain (xylindein) in the substrate. A pale yellow ionomidotic reaction, observed in C. glauca, has not been observed before in this genus. The long and narrow protruding cells on the surface of apothecia, called tomentum hyphae or hairs (Dixon 1975; Johnston and Park 2005, Huhtinen et al. 2010), characteristic of Chlorociboria species, are less prominent in C. glauca. The species grows on corticated branches of various woody substrates, including Rubus spp. In the sample from Ireland, the inhabited branch projected into the air. C. glauca can tolerate desiccation as a few mature asci and many ascospores were still viable ten days after drying under inside air humidity. By contrast, most other lignicolous Chlorociboria form apothecia on decorticated branches or trunks that lie on moist ground. In the multigene analysis Chlorociboria glauca formed a strongly supported clade with C. aeruginosa and C. aeruginascens (Fig. 1), whereas in analyses of the ITS region the relationship of C. glauca with these two and species from the Southern Hemisphere remained unresolved (Fig. S5). Chlorociboria aeruginella, a hairy blue-green fungus growing on stems of Filipendula, appeared to be genetically more distant than the other two species common in the Northern Hemisphere (Fig. 1). In the ITS phylogeny it formed a strongly supported group with C. halonata from New Zealand (Fig. S5). Considering the unusually high 11–17 % interspecific variation in the ITS regions, observed also by Johnston and Park (2005), and the lack of support to the genus both in multigene and ITS analyses, current Chlorociboria obviously includes distinct phylogenetic lineages. However, resolving their phylogenetic relationships and generic delimitation in the group warrants expanding the current multigene analyses.
Type specimen examined: UNITED KINGDOM, Scotland, Argyll and Bute, isle of Mull, Croggan, ~56.381°N 5.716°W, alt. ~20 m, Corylus avellana, on dead branch, 29 Sep. 1972, M.C. Clark (K(M) 41444 holotype). Additional specimens examined: UNITED KINGDOM, North-Ireland, 16.5 kmWNWof Enniskillen, 3.8 km WSW of Derrygonnelly, Knockmore, 54.4017°N 7.867°W, alt. 253 m, on grassland, projecting branch of Prunus spinosa, on bark covered with moss, 24 Oct 2012, leg. A. Gminder, det. J. H.
Petersen & A. Gminder (J.H.P.-12.344). FRANCE, Bourgogne, Saône-et-Loire, 8 km NE of Le Creusto, 2 km
NNW of St.-Pierre-de-Varennes, Étang de Brandon, 46.8587° N 4.492°E, alt. 395 m, Salix sp., on corticated
branch, 10 Dec 2009, J.P. Dechaume, det. H.O. Baral (H.B.9232, TAAM 198458, KL238); ibid. with anamorph, on Rubus fruticosus dead canes (H.B. 9236, TAAM 198459, KL237). SPAIN, Asturias, Cangas de Onís, 2.5 km SE of Covadonga, alt. 535 m, 15 Mar 2008, branch of Rosa sp., on
bark, J. Linde, vid. E. Rubio (E.R.D. 4401).