Julella Fabre, Annls Sci. Nat., Bot.

Ariyawansa, Hiran A., Jones, Evan B. G., Suetrong, Satinee, Alias, Siti A., Kang, Ji-Chuan & Hyde, Kevin D., 2013, Halojulellaceae a new family of the order Pleosporales, Phytotaxa 130 (1), pp. 14-24 : 20-22

Julella Fabre, Annls Sci. Nat., Bot. , sér. 6, 9: 113. 1879 [1878].

MycoBank MB 2539

Putative synonymy:

Catharinia (Sacc.) Sacc., Syll. fung. (Abellini) 11: 350. 1895.

Hyalospora Nieuwl., Am. Midl. Nat. 4: 377. 1916.

Peltosphaeria Berl., Revue mycol., Toulouse 10: 18. 1888.

Pleospora subgen. Catharinia Sacc., Syll. fung. (Abellini) 2: 275. 1883.

Polyblastiopsis Zahlbr. , in Engler & Prantl, Nat. Pflanzenfam., Teil. I (Leipzig) 1*: 65. 1903.

Saprobic or possibly lichenized. Ascomata immersed, becoming erumpent to nearly superficial, sphaeroid, black, coriaceous, ostiolate, formed under a clypeus. Ostiole usually widely porate, with a short neck, ostiolar canal filled with a tissue of hyaline cells. Peridium two layered, outer wall composed of small, dark brown to black, heavily pigmented, thick-walled cells of textura angularis and fusing with the host at the outside, inner wall comprising broad yellowish brown cells of textura angularis, thick at the apex and thinner at the base. Hamathecium of dense broad, septate, cellular, pseudoparaphyses anastomosing and branching and embedded in mucilage. Asci 2-spored, bitunicate, fissitunicate, clavate to cylindrical, with a short, broad, furcated or knob-like pedicel, rounded at apex and without a distinct ocular chamber. Ascospores biseriate or partially uniseriate, asymmetric or nearly symmetric, hyaline, obovoid, fusoid, or elongate, multi-septate, muriform, verruculose, wall thin, surrounded by a mucilaginous sheath, guttulate, constricted at the septa.

Notes. Julella has been variously confused, with some species being saprotrophic on bark, while others are lichenized, and the delineation of the genus is poorly defined. Currently 46 epithets are listed in Index Fungorum (http://www.indexfungorum.org/Names/Names.asp, Accession Date - 02 January 2013). Many of the species assigned to the genus are facultatively lichenized with the alga Trentepohlia as the photobiont ( Purvis et al. 1992). Julella shares many common features with Peltosphaeria but differs in having bisporous asci ( Barr 1985). Barr (1985) proposed Peltosphaeria as a synonym of Julella . Various treatments of Julella are by Barr (1985) who lists three species and one variety in Julella , and Aptroot and van den Boom (1995) who considered Julella a predominantly tropical group of bark saprotrophs, and recognized the species: J. lactea (A. Massal.) M.E. Barr , J. sericea (A. Massal.) Coppins (= J. fallcaiosa (Stizenb. ex Arnold) R.C. Harris ) and J. vitrispora (Cooke & Harkn.) M.E. Barr ( J. sublactea ), and regarded other species as synonyms or assigned them to other genera. We have examined type material of the genus Julella from S, and the following description is based on examination of the holotype J. buxi . Our circumscription of the genus is in a strict sense based on the type species as molecular data is needed to confirm placement of other, especially lichenized taxa.

Because of the differences in opinion surrounding taxa which should be included in the genus Julella has been assigned to Amphisphaeriaceae (Lindau in Engler and Prantl 1897), Pleosporaceae (Lutrell 1973; von Arx and Müller 1975) and Arthropyreniaceae ( Barr 1985) . Lumbsch and Huhndorf (2010) assigned Julella to Thelenellaceae , a family of Ostropomycetidae. Zhang et al. (2012) suggested that with the exception of hyaline ascospores, most of the characters of Julella are compatible with Montagnulaceae . The circumscription of Julella above is thus based on the type species until relationships with other taxa can be confirmed by molecular data.

Generic type: Julella buxi Fabre, Annls Sci. Nat., Bot. , sér. 6, 9: 113. 1878. ( Fig. 3A–M )

MycoBank MB167562

Saprobic on woody substrates. Ascomata 200-350 µm high, 190-250 µm wide, immersed becoming erumpent to nearly superficial, sphaeroid, black, coriaceous, ostiolate, formed under a clypeus. Ostiole usually widely porate, with a short neck, ostiolar canal filled with a tissue of hyaline cells. Peridium two layered, outer wall composed of small, dark brown to black, heavily pigmented, thick-walled cells of textura angularis and fusing with the host at the outside, inner wall comprising broad yellowish brown cells of textura angularis, thick at the apex and thinner at the base. Hamathecium of dense, 2-4 µm broad, septate, pseudoparaphyses anastomosing and branching above the acsi and embedded in mucilage. Asci 90-130 × 25-35 µm, 2-spored, bitunicate, fissitunicate, clavate to cylindrical, with a short, broad, furcated or knob-like pedicel, rounded at apex and without a distinct ocular chamber. Ascospores 30-35 × 10-15 µm biseriate or partially uniseriate, asymmetric or nearly symmetric, hyaline, obovoid, fusoid, or elongate, multi-septate, muriform, verruculose, wall thin, surrounded by a mucilaginous sheath, guttulate, constricted at the septa. Asexual State: Unknown

Material examined. France, Serignan , on Buxus sempervirens, H. Fabre ( S F5992 ; holotype) .

Notes. Julella buxi occurs on the bark of Buxus sempervirens and is non-lichenized. No asexual morph was found on the type material. Julella herbatilis differs from J. buxi by the herbaceous substrate, sparsely developed clypeus, a hamathecium of pseudoparaphyses without gelatinous matrix, 8-spored asci, and ascospores with only one or two longitudinal septa ( Kohlmeyer et al. 1997).

Figures

FIGURE 3. Julella buxi (holotype). A–C. Surface view of ascomata on host substrate (bark). D–E. Longitudinal section ascoma with clypeus. F. Close up of the peridium. g. Broad, septate pseudoparaphyses. H–J. Two spored asci lacking an ocular chamber. K–L. Muriform ascospores. M. Ascospore mounted in Indian ink to show mucilaginous sheath. Scale bars: D–E = 80µm, F = 10 µm, H–J = 25µm, K–M = 15 µm.