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Page number:19 
Remarks (internal):The typification of Didymosphaeria has caused problems. The genus originally consisted of six species. Most authors selected Didymosphaeria epidermidis (Fries) Fuckel as type, but the first lectotype ever chosen formally seems to have been Didymosphaeria peltigerae Fuckel, which is a Polycoccum. This selection was made by Theissen & Sydow, using the first-species rule. However, this species conflicts with the protologue, as it is not `corticola', although it could have been regarded as growing on the cortex of a lichen. The type material of Didymosphaeria epidermidis consists only of coelomycetes. The type of the only original species which may be a Didymosphaeria in the present sense, Didymosphaeria rubi, could not be found in G or in any other herbarium. Therefore Hawksworth & David (1989: 494) proposed to conserve the genus with a lectotype specimen, Fungi Rhenani 1770. This proposal has been accepted by the Yokohama Botanical Congress (1993), in agreement with the Committee for Fungi of the International Association of Plant Taxonomists.
Several other genera have been reported to be synonymous with Didymosphaeria, but are now regarded to have other affinities, e.g. Phaeodothis Sydow (separate genus, see Aptroot, 1995), Rhynchostomopsis Petrak & Sydow (= Amphisphaeria), and Roussoëlla Saccardo (separate genus, see Aptroot, 1995).
Description type:Non-original description 
Description:Didymosphaeria Fuckel, Jb. nassau. Ver. Naturk. 23-24: 140. 1870, nom. cons.
Type , GERMANY: À–strich, on Berberis vulgaris (Berberidaceae). Fuckel s.n., s.d., distributed in Fungi Rhenani 1770 (S, typus conservandus (see Gams (1995) and Hawksworth & David (1989: 494); BR, W, Z, isolectotypes, all sub Amphisphaeria epidermidis) (= Didymosphaeria futilis (Berkeley & Broome) Rehm).
Didymosphaerella Cooke, Grevillea 19: 3. 1890.
Type , Didymosphaerella filicina Cooke (= Didymosphaeria futilis (Berkeley & Broome) Rehm) (holotype).
Didymascina Höhnel, Annls mycol. 3: 331. 1905.
Type , Didymascina salicicola (Allescher) Höhnel (= Didymosphaeria futilis (Berkeley & Broome) Rehm) (holotype). Synonymy follows Von Höhnel (1909).
Cryptodidymosphaeria (Rehm) Höhnel, Sber. Akad. Wiss., Wien, math.-nat. Kl. 126: 359. 1917 º Didymosphaeria subgenus Cryptodidymosphaeria Rehm, Annls mycol. 4: 265. 1906.
Type , Cryptodidymosphaeria conoidea (Niessl) Höhnel (º Didymosphaeria conoidea Niessl) (holotype).
Haplovalsaria Höhnel, Sber. Akad. Wiss., Wien, math.-nat. Kl. 128: 583. 1919.
Type , Haplovalsaria simplex Höhnel (= Didymosphaeria sp., indeterminable, in bad condition, fide Müller & Von Arx, 1962) (holotype).
Massariellops Curzi, Atti Ist. Bot. Univ. Pavia 3: 162. 1927.
Type , Massariellops aprutina Curzi (= Didymosphaeria futilis (Berkeley & Broome) Rehm) (holotype).
Stroma forming an internal (formed inside the outer periderm layer, Figs 2, 3) to external clypeus around the ostiole, black, but often reduced. Ascomata pseudothecioid, globose to pyriform, black, smooth, simple, immersed to erumpent. Subiculum none. Peridium narrow at base and sides, hyaline to pale brown or (rarely) black, consisting of an internal layer of hyaline to pale brown, flattened hyphae (textura intricata) and an external layer of pale brown to black, elongated hyphae (textura intricata, Fig. 4), IKI-negative, KOH-negative. Hamathecium consisting of trabeculate pseudoparaphyses, simple between the asci, anastomosing above (Fig. 1), colourless, IKI-negative. Asci cylindrical, bitunicate, with a small, c. 2 ?m wide, ocular chamber, IKI-negative, with 8 ascospores in one row. Ascospores ellipsoid to long-ellipsoid, brown to grey, with gelatinous distoseptate wall thickenings leaving rounded lumina, asymmetrically or symmetrically 1-septate, constricted near the septum or not, with or without minute spinulose, coarsely [p. 20] spinose, coarsely striate or foveate ornamentation, without germ locus, covered with a thin gelatinous sheath.
Anamorphs sometimes formed in culture, of two types, one forming pycnidia (Phoma-like), the other a hyphomycete (Fusicladiella Höhnel). Both anamorphs have been reported by Scheinpflug (1958, as Dendrophoma and an unidentified hyphomycete, respectively).
Distribution and ecology: Cosmopolitan, in and on wood, leaves and stems of various plants, and also on linoleum. Although over 550 taxa have been attributed to this genus, only seven species are recognized here.
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