Dendrostoma mali X.L. Fan & C.M. Tian.

Sexual morph: pseudostromata immersed in bark and erumpent, causing a pustulate bark surface, consisting of an ectostromatic disc and entostroma with embedded ascomata. Ectostromatic disc flat or convex, surrounded by bark flaps. Entostroma light-coloured, prosenchymatous to nearly pseudoparenchymatous, mixed with bark cells, sometimes forming a more-or-less conical central column beneath the disc. Stromatic zones lacking or sometimes bark dorsally darkened. Ascomata perithecial, subglobose. Ostioles flat in the disc or slightly projecting, cylindrical, often with conical apical part. Paraphyses deliquescent. Asci oblong, fusoid, narrowly clavate or subellipsoid, with a refractive apical ring, containing (4–)6–8 ascospores in various arrangements, becoming detached at maturity. Ascospores hyaline, ellipsoid, fusoid, oblong to subacicular, often inequilateral, straight to curved, bicellular, more-or-less constricted at the median or eccentric septum, smooth, with 2–4 drops or multiguttulate, often with gelatinous terminal appendages. Asexual morph: conidiomata acervular, either forming lateral locules on the ostiolar level of sexual pseudostromata or separate, conical to pulvinate, immersed-erumpent from bark; wall pseudoparenchymatous. Often a pseudoparenchymatous conical central column present beneath the covering layer. Conidiophores non-differentiated, hypha-like or reduced to conidiogenous cells. Conidiogenous cells phialidic, lining the inner walls of cavities, subcylindrical to ampulliform, hyaline, shades of brown with age. Conidia hyaline, aseptate, smooth, multiguttulate or not, thin-walled, oblong, ellipsoid to fusoid, straight or curved.

Dendrostoma atlanticum is recognized by clay-coloured ectostromatic discs and ascospores having large guttules and bristle-like appendages.

France, Bretagne, Dépt. Morbihan (56), Saint Martin sur Oust, Beauvais, on twigs of Castanea sativa, soc. immature Valsaria sp., 15 Jan. 2016, A. Delannoy (WU 37024; ex-type culture CBS 145804 = D196).

Atlanticum, referring to its occurrence in the Atlantic region.

Sexual morph: pseudostromata 1–4.5 mm in their widest dimension in cross section, bluntly conical or pulvinate, circular, elliptic or irregular in outline, scattered, gregarious to confluent up to 7 mm length. Ectostromatic discs 0.4–2 mm in their widest dimension, distinct and conspicuous, projecting up to 0.5(–1) mm from the bark surface, pulvinate, circular, angular or fusoid in outline, with flat or convex top, initially whitish, turning pale to dark clay-coloured, splitting the periderm, often surrounded by bark flaps. Ostioles 1–40 per disc, often originating eccentrically from the perithecial venter, arranged in ring-like configuration or variably filling the disc, (44–)100–163(–195) µm (n = 42) in diameter at the tip, brown to black, cylindrical, sometimes attenuated towards tip, plane with the disc or projecting up to 300 µm; tip usually with dark umbilicate centre. Entostroma whitish, yellowish to pale bark coloured, consisting of thin-walled, hyaline to subhyaline 1–3 µm wide hyphae and bark cells. Perithecia (390–)480–660(–750) µm (n = 35) in diameter, depressed subglobose, collapsing upward upon drying; peridium ca 10–30 µm thick, colourless to pale olivaceous, consisting of hyaline to yellowish or pale brownish, thick-walled cells without clear contours, smaller and more-or-less isodiametric outside, larger and compressed inside, very variable, (3–)4–17(–38) in diameter (n = 66). Paraphyses of broad collapsing threads. Asci (64–)71–86(–90) × (11–)13–17(–19) µm (n = 35), fusoid to oblong, being released at maturity, containing 8 biseriate ascospores. Ascospores (13–)15–18(–20) × (4.3–)5.5–7(–8) µm, l/w (2.1–)2.4–2.9(–3.9) (n = 51), ellipsoid, often inequilateral, 2-celled, slightly constricted at the median septum, with the upper cell often slightly wider than the lower, hyaline, with 1–2 large and several small guttules per cell, smooth, with a hyaline, bristle-like, straight to curved appendage (10–)11.5–15.5(–21) × (1.5–)2–2.5(–2.8) µm (n = 101) at each end.

Asexual morph acervular. Conidiomata ca 1–2.2 mm in diameter, bluntly conical, width exceeding height, prosenchymatous. Covering discs 0.3–1.1 mm in diameter, flat to pulvinate, whitish cream to pale reddish brown. Central column whitish to reddish brown, usually darker toward the top; fertile chamber ring-like around the central column; walls and column consisting of pale yellowish brown textura angularis, outer wall and outer layer of the column containing numerous crystals. Phialides (3.7–)6.3–9.7(–11.5) × (2–)2.5–3.8(–4.7) µm (n = 46), arranged in a palisade on hyaline to yellowish, angular cells, ampulliform to lageniform, less commonly cylindrical. Conidia 1-celled, hyaline, smooth, dimorphic, both morphs formed in the same locule, either ellipsoid to oblong, (6.4–)7.7–10.2(–11.7) × (4–)4.5–5.7(–6) µm, l/w (1.4–)1.4–2.2(–3) (n = 21), with a large guttule and often distinct abscission scar, or cylindrical, (7.7–)10.2–13.5(–15.3) × (2.3–)2.5–3.2(–3.5) µm, l/w (2.8–)3.6–4.7(–5.6) (n = 45), straight or curved, with mostly 3 or 4 confluent guttules.

On CMD at 16 °C in the dark colony more-or-less circular, of loose mycelium, first white, variably covered by white aerial hyphae, becoming dense, forming white and apricot to orange zones, darkening and turning black from the centre, sometimes forming reddish brown dots, spots or tubercles.

Spain, Galicia, Pontevedra, O Grove, 42°28'04"N, 08°53'14"W, on twigs of Castanea sativa, 4 Nov. 2018, M.A. Delgado (WU 37025; culture D303).

Dendrostoma atlanticum is easily recognized by its long-pedicellate ascospores having 2–4 large drops, setting it apart from D. castaneum, which has narrow, often curved ascospores with small drops and short appendages. All species described from Castanea in China are only known from asexual morphs (Jiang et al. 2019).

Figure 3. 

Dendrostoma atlanticum. Sexual morph a–d ectostromatic discs and ostioles e pseudostroma in vertical section f pseudostroma in cross section g peridium in cross section (in 3% KOH) h–k asci l–r ascospores. a–c, f, h, i, k–p WU 37024 = D196), d, e, g, j, q, r WU 37025 = D303. Scale bars: 1 mm (f), 500 µm (a–e), 10 µm (g–r).

Figure 4. 

Dendrostoma atlanticum (WU 37024 = D196). Asexual morph a, b conidiomata in face view c conidioma in vertical section d vertical section through fertile chamber and part of the central column e, f phialides g–l conidia (cylindrical in g–j, ellipsoid in k, l). d–l In 3% KOH. Scale bars: 300 µm (a–c), 100 µm (d), 10 µm (e), 5 µm (f–l).

Dendrostoma castaneum is recognized by KOH+ purple ostioles, slender ascospores with small drops and subfusiform conidia, and the presence of hyphal conidiophores.

Sexual morph: pseudostromata 0.8–3(–5) mm in their widest dimension in cross section, very variable, flat subconical or lenticular, in outline circular, elliptic or elongate, scattered, gregarious or confluent, and forming elongate patches, lifting the periderm slightly and often becoming visible as a dark zone on the bark surface, causing bumps in bark, splitting the periderm. Ectostromatic discs 0.3–2.7 mm in their widest dimension, often ill-defined and variable, cream, yellowish brown to dark brown, flat, surrounded by bark flaps, first present as a covering layer with ostiolar necks subsequently bursting through it, soon crumbling away. Ostioles 1–25 per disc, usually arising eccentrically from the perithecial venter, (53–)71–125(–180) µm (n = 51) in diameter, bluntly conical or cylindrical with black sides and red, yellowish, or greenish tip, often attenuated to a minute, ca 20–40 µm wide dark centre, in section rounded to angular, sometimes sulcate, variably arranged in the disc, projecting to 0.2 mm, periphysate; red colour of the ostiolar tip turning purple in 3% KOH and yellow in lactic acid. Entostroma yellowish to shades of brown, consisting of bark cells and hyaline to yellowish, 1.5–4.5 wide, thin-walled hyphae becoming thicker-walled and forming a pseudoparenchyma in the vicinity of perithecia. Perithecia tightly aggregated, (265–)305–460(–600) µm (n = 47) in diameter, depressed subglobose to ellipsoid, collapsing upward; peridium ca 10–30 µm thick, hyaline, pale olivaceous to brown, in section outside of brown isodiametric to strongly compressed thick-walled cells, inside of compressed and elongated hyaline to brownish cells, in combination (3–)4–15(–28) µm (n = 57) in diameter. Paraphyses absent at maturity. Asci (49–)53–63(–65) × (7.8–)8.5–10.5(–12) µm (n = 35), narrowly clavate to subfusoid or oblong, floating freely in the centre, thick-walled at the apex containing a minute refractive ring invisible in 3% KOH, containing 4–8 biseriate ascospores. Ascospores (11.5–)14–18(–20) × (3–)3.5–4.5(–5.3) µm, l/w (2.7–)3.5–4.6(–5.4) (n = 76), 2-celled, not or slightly constricted at the median or slightly eccentric septum, oblong to inequilaterally ellipsoid, straight to mostly curved, with the upper cell often slightly wider than the lower, broadly rounded at the ends, hyaline, with several minute drops (confluent to 2 larger drops per cell in mounts), smooth, with or without a hyaline, subconical to filiform appendage (2.2–)2.8–4.5(–5.5) × (1.1–)1.3–1.6(–1.8) µm (n = 88) at each end invisible in 3% KOH.

Asexual morph co-occurring with the sexual morph, acervular, pulvinate, scattered to aggregated, 0.5–2.7 mm in diameter, appearing as superficial discs 0.3–2 mm in diameter, with undulate surface, cream to pale brown and becoming brittle in the centre and nearly black at the periphery and often also indicated as dark zone on the bark surface around the disc; inside consisting of a pale or yellowish brown, loose and brittle central column consisting of pale brown t. prismatica and a lateral ring-like, dense, white to distinctly yellow fertile part with even or undulating margin, the latter also raising above the column, outside surrounded by a partly undulating, ca 20–25 µm thick black wall consisting of dark brown textura angularis of cells 4–10 µm in diameter at apical and upper peripheral regions, becoming paler downward and being absent at the base and lower sides. Interior of the fertile chambers consisting of isodiametric to elongate hyaline supporting cells and richly and irregularly branched hyphal conidiophores bearing phialides and conidia. Wall, supporting cells and phialides turning dilute violaceous in 3% KOH. Phialides arranged on supporting cells in palisades along the walls and on conidiophores, (6–)8.2–12(–15.3) × (1.7–)2.5–3.5(–5) µm (n = 80), repetitive, mostly lageniform, often with long necks; conidia also formed on cylindrical pegs and denticles. Conidia (6–)6.7–8(–8.8) × (2.5–)3–3.5(–3.7) µm, l/w (1.7–)2.1–2.6(–3.1) (n = 85), subfusiform, subclavate or ellipsoid, scar often distinct, smooth, with few minute drops.

On CMD at 16 °C in the dark colony circular, dense, white, covered by white cottony aerial hyphae, partly turning pale apricot, reverse orange, not zonate.

(all on recently detached twigs of Castanea sativa on ground). AUSTRIA, Burgenland, Forchtenstein, Kohlstatt, 13 Feb. 2016, H. Voglmayr (WU 37026); Steiermark, near highway A2 exit Steinberg, grid square 9057/1, 26 Oct. 2000, W. Jaklitsch W.J. 1651 (WU 37027); same locality, soc. Cytospora sp., 3 Nov. 2015, W. Jaklitsch & H. Voglmayr (WU 37028; culture CBS 145803 = D192). ITALY, Sicilia, Etna, above Zafferana Etnea, soc. Cytospora sp. (Valsa morph), 17 June 2016, H. Voglmayr & W. Jaklitsch (WU 37029; culture D260); Veneto, Selva di Montello, 8 Apr. 2016, H. Voglmayr & W. Jaklitsch (WU 37030; culture D230).

Sizes of pseudostromata and acervuli strongly depend on twig thickness. Remarkably, red colour of the ostiolar tip, when present, turns purple in 3% KOH and yellow in lactic acid, a feature, which is typical of the Hypocreales and within the Diaporthales otherwise only found in the Cryphonectriaceae.

So far, confirmed records of D. castaneum are only known from Europe where the species is widely co-occurring with its host, Castanea sativa. Kobayashi (1970) reported and illustrated D. castaneum (as Cryptodiaporthe castanea) from Castanea crenata and C. mollissima in Japan. However, it is unlikely that these collections are conspecific with the European D. castaneum, considering their different spore shape and hosts. The 1 or 2 large guttules per ascospore cell and the ascospore appendages illustrated in Kobayashi (1970: fig. 32) are similar to D. atlanticum rather than to D. castaneum. Remarkably, he also reported and illustrated dimorphic conidia for the Japanese collections, which we also observed in D. atlanticum. Considering hosts and distribution, the Japanese collections likely represent one of the species described by Jiang et al. (2019) or an undescribed species.

Figure 5. 

Dendrostoma castaneum. Sexual morph a–d ectostromatic discs and ostioles (in a ostioles breaking through covering layer) e pseudostroma in vertical section f pseudostroma in cross section g peridium in section (in 3% KOH) h–k asci l–s ascospores a, c–g, j, k, s WU 37030 = D230 b, n–r WU 37026 h, i, l, m WU 37028 = D192. Scale bars: 500 mm (a, c, d, f), 200 µm (b, e), 20 µm (g), 5 µm (h–s).

Figure 6. 

Dendrostoma castaneum (WU 37030 = D230). Asexual morph a conidioma in face view b conidioma in cross section c, d conidiomata in vertical section e outer upper wall of fertile chamber f wall, short conidiophores and phialides (note violaceous tone) g, h phialides and hyphal conidiophores i–m conidia f–m In 3% KOH. Scale bars: 300 µm (a–d), 10 µm (e–g), 5 µm (h, i), 3 µm (j–m).

Dendrostoma creticum is recognized by long, subacicular ascospores.

Greece, Crete, near Askifou, 35°17'47"N, 24°12'33"E, on twigs of Quercus coccifera, soc. Cytospora (Valsa morph) sp., 6 June 2015, H. Voglmayr & W. Jaklitsch (WU 37031; ex-type culture CBS 145802 = D124)

Creticum, referring to its occurrence, Crete.

Sexual morph: pseudostromata 0.6–1.6 mm in their widest dimension in cross section, pulvinate, circular, elliptic or irregular in outline, scattered, gregarious to confluent up to 4 mm length, causing small bumps in the bark, splitting the periderm. Ectostromatic discs 0.25–1.4 mm in their widest dimension, medium to dark brown, flat or convex, surrounded by bark flaps. Ostioles 1–7 per disc, (31–)55–102(–135) µm (n = 40) in diameter at the rounded tip, dark brown to black, bluntly conical, plane with the disc or slightly prominent. Entostroma pale bark coloured, mottled. Perithecia (245–)320–445(–495) µm (n = 30) in diameter, depressed-subglobose, collapsing upward; peridium ca 10–50 µm thick, a dark brown textura angularis in face view, in section outside of dark brown textura angularis to strongly compressed cells (4–)7–14(–18) µm (n = 30) in diameter, inside of strongly compressed and elongated hyaline cells. Paraphyses absent at maturity. Asci (66–)71–85(–94) × (8.8–)9.5–11.2(–12.3) µm (n = 44), narrowly clavate to subfusoid, floating freely in the centre, containing 8 bi- to triseriate ascospores. Ascospores (26–)33–45.5(–52) × (2.7–)3–3.7(–4.6) µm, l/w (6.8–)9.8–14.3(–17.5) (n = 40), 2-celled, slightly constricted at the median or often distinctly eccentric septum, oblong, straight to curved, with the upper cell often slightly wider than the lower, hyaline, multiguttulate, smooth, with or without a hyaline subconical appendage (1.4–)1.5–2.3(–3.2) × (0.6–)0.9–1.3(–1.5) µm (n = 25) at each end.

Asexual morph unknown.

On CMD at 16 °C in the dark colony circular to irregular, dense, white, partly covered by short, white aerial hyphae, zonate, soon turning dark brown to black with pale apricot spots and margin and apricot to orange pigment diffusing into agar, reverse dark brown with orange margin.

Dendrostoma creticum is similar to the closely related D. istriacum but differs by distinctly longer ascospores, darker ectostromatic discs and a different host species.

Figure 7. 

Dendrostoma creticum (WU 37031 = D124). a, b, d Ectostromatic discs and ostioles in face view c pseudostroma in cross section e peridium in cross section in 3% KOH f–i asci j–r ascospores. Scale bars: 200 µm (a, b, d), 500 µm (c), 10 µm (e–r).

Dendrostoma istriacum is recognized by narrow, oblong ascospores with small drops.

CROATIA, Istria, Rovinj, near Kamp Amarin, 45°06'33"N, 13°37'02"E, on twigs of Quercus ilex, soc. Diplodia sp., 14 May 2015, H. Voglmayr (WU 37032; ex-type culture CBS 145801 = D122).

Istriacum, referring to its occurrence, Istria.

Sexual morph: pseudostromata 0.6–1.5 mm in their widest dimension in cross section, pulvinate, circular or elliptic in outline, scattered or tightly aggregated in large numbers, causing bumps in the bark and bark lesions to ca 3.2 mm long parallel to the twig axis. Ectostromatic discs 0.15–0.7 mm in diameter, mostly inconspicuous, surrounded by bark flaps, flat or convex, prosenchymatous, first whitish, turning pale to dark brown, becoming disintegrated and replaced by black ostioles and perithecial tops. Entostroma whitish to pale bark coloured. Stromatic tissues consisting of bark cells and 2–4 µm wide, hyaline to brown hyphae. Ostioles 1–5 per disc, (45–)61–91(–103) µm (n = 30) in diameter, short cylindrical, slightly projecting from the disc, brown to black; wall consisting of dark brown textura angularis. Perithecia (230–)280–393(–443) µm (n = 20) in diameter, globose to subglobose; peridium ca 15–35 µm thick, pale olivaceous to dark brown, consisting of 2–4 cell layers of thick-walled, dark brown angular cells (3–)4–13.5(–20.5) µm (n = 40) in diameter outside and long compressed, thin-walled, hyaline to brownish cells inside. Paraphyses absent at maturity. Asci (59–)62–70(–74) × (7–)8.5–10(–11) µm (n = 30), fusoid to narrowly clavate, floating freely in the centre, containing 8 bi- to triseriate ascospores. Ascospores (19.3–)20.5–25.5(–29.5) × (3–)3.5–4.2(–5.1) µm, l/w (4.5–)5.3–7(–8.7) (n = 40), 2-celled, constricted at the more-or-less median septum, oblong, straight to curved, with the upper cell often slightly wider than the lower, hyaline, containing several small guttules concentrated towards the ends and the septum, smooth, with a hyaline subconical appendage (1.7–)2.5–3.5(–4.5) × (0.8–)1–1.3(–1.5) µm (n = 40) at each end, becoming elongated in mounts.

Asexual morph: conidiomata ca 250–520 µm in diameter, acervular, inconspicuous, immersed in bark, causing small bark bumps, becoming visible in fissures, whitish to brownish, flat or convex, bluntly conical, usually broader than high, consisting of a broad sterile greyish brown central column, a white outer fertile ring and a brown covering layer; also fertile between the latter and the top of the column. Covering layer consisting of a dark brown textura angularis of 4–10 µm wide cells, turning paler to hyaline and more rounded downwards; column comprising pale brown textura angularis-epidermoidea of similarly sized cells; outer margin of the fertile ring consisting of a narrow layer of hyaline to pale brown, angular to compressed cells; gel surrounding rounded to angular, subhyaline to hyaline cells supporting phialides slowly turning pinkish in 3% KOH. Phialides forming palisades in fertile areas, tightly packed, cylindrical to ampulliform, often with long acute necks, (5.5–)6.3–9(–11) × (1.8–)2.2–3.7(–5.3) µm (n = 33). Conidia (4–)5–6.6(–7.4) × (1.9–)2.1–2.5(–2.7) µm, l/w (1.6–)2.1–3(–3.7) (n = 53), oblong to ellipsoid, 1-celled, hyaline, smooth, usually with distinct abscission scar.

On CMD at 16 °C in the dark, colony circular to irregular, dense, white, partly covered by short white aerial hyphae, zonate, soon turning dark brown to black with pale apricot to reddish brown spots and margin and some pale apricot pigment diffusing into agar, reverse dark brown with pale apricot margin.

CROATIA, Istria, Rovinj, near Kamp Veštar, 45°03'19"N, 13°40'55"E, on twigs of Quercus ilex, 30 May 2019, H. Voglmayr (WU 37033).

Dendrostoma istriacum is closely related to D. creticum but differs from that species by distinctly shorter ascospores and a different host species.

Figure 8. 

Dendrostoma istriacum (WU 37032 = D122). a–y Sexual morph a–c ectostromatic discs and ostioles d pseudostroma in cross section e peridium in cross section f–j, o–y ascospores k–n asci z–h1 asexual morph z conidioma in vertical section a1 upper part of conidioma showing covering layer, upper part of central column and fertile layers with opening at the upper right side b1 peripheral fertile chamber in vertical section c1 conidia attached to phialides d1–e1 phialides f1–h1 conidia; e, c1–h1 In 3% KOH. Scale bars: 150 µm (a–c, z), 300 µm (d), 100 µm (b1), 50 µm (a1), 10 µm (e–y, c1–e1), 5 µm (f1–h1).

Dendrostoma leiphaemia is recognized by conspicuous ectostromatic discs, broad conical ostiolar necks, and broad multiguttulate ascospores.

Sexual morph: pseudostromata 1–5 mm in their widest dimension in cross section, pulvinate to conical, circular, elliptic or irregular in outline, scattered, aggregated to confluent, sometimes forming lines of up to 15 mm length, causing conspicuous bumps and lesions in the bark; dark brown dorsal zones present within the bark, absent in basal regions. Ectostromatic discs 0.35–2.5 mm in their widest dimension, conspicuous, whitish, cream, pale brown, pale yellowish brown to dull brown, fusoid, triangular to circular in section, flat or convex, often surrounded by bark flaps, elevated up to 1.3 mm beyond the bark surface, brittle to powdery, first present as a covering layer with ostiolar necks subsequently bursting through it, eventually crumbling away. Ostioles 1–30 per disc, (88–)124–220(–336) µm (n = 64) in diameter, dark brown, black, or reddish brown with black, rarely yellowish tip, cylindrical with conical apical part, attenuated to 35–90(–180) µm at the rounded, compressed or coarsely sulcate tip, projecting to 250, less commonly 400 µm, white, in upper regions sometimes yellow inside, periphysate, arising centrally to eccentrically from the perithecial venter and slightly convergent above perithecia; turning partly yellow, partly brown in 3% KOH. Entostroma whitish to pale yellowish or pale bark-coloured, prosenchymatous to pseudoparenchymatous, the latter particularly in the vicinity of perithecia, consisting of 1.5–5 µm wide hyphae or angular cells, mixed with bark cells. Perithecia arranged in valsoid configuration, tightly aggregated, (292–)380–625(–700) µm (n = 21) in diameter, globose to depressed-subglobose, with gelatinous contents, collapsing upward; peridium ca 7–35 µm thick, pale olivaceous to dark brown, consisting of an outer layer of isodiametric to elongate, thick-walled dark brown cells and an inner layer of compressed elongate, hyaline to brownish, thin-walled cells (5–)6.5–16(–22.5) µm (n = 31). Paraphyses absent at maturity. Asci floating freely in the centre when mature, (49–)58–71(–80) × (9–)10–13.5(–17.5) µm (n = 56), clavate, oblong, fusoid to subellipsoid, with a refractive apical ring, containing 8 bi- to triseriate, fasciculate or obliquely uniseriate ascospores. Ascospores (15–)16–19(–21) × (3.8–)4.3–5.2(–5.8) µm, l/w (2.7–)3.3–4.1(–4.7) (n = 95), 2-celled, not or slightly constricted at the median or slightly eccentric septum, inequilaterally ellipsoid or oblong, straight or curved, with the upper cell sometimes slightly wider than the lower, hyaline, multiguttulate, smooth, lacking appendages.

Asexual morph co-occurring with the sexual morph, acervular, either present as locules in lateral regions of pseudostromata above perithecia or forming separate, conical to pulvinate, dorsally blackened acervuli 0.9–2.2 mm in diameter, with conical upper part or whitish to cream or brownish, more-or-less circular, continous or deeply fissured discs ca 0.4–1 mm in diameter and whitish-cream, partly hollow interior containing slightly darker fertile chambers meandering through it. Walls and interior consisting of brown or hyaline to pale yellowish brown textura angularis. Phialides lining inner wall of the cavity, sessile, (4.8–)6.5–11(–12.7) × (1.7–)2–3.8(–5.3) µm (n = 16), subcylindrical to lageniform, reddish brown in 3% KOH (when old). Conidia (4.8–)7–9.5(–11) × (1.5–)1.8–2.3(–2.5) µm, l/w (2.3–)3.3–4.9(–6.3) (n = 50), unicellular, cylindrical, oblong, subclavate, rhomboid or narrowly ellipsoid, straight to slightly curved, often with a truncate or acute end, hyaline, turning pinkish-yellowish in 3% KOH, smooth, with minute terminal drops, adhering together in masses when old.

On CMD at 16 °C in the dark, colony irregular or dimorphic, dense, white, partly covered by short white aerial hyphae, zonate, soon turning dark brown to black with red or reddish brown spots, reverse dark brown, reddish brown with white, pale apricot or reddish brown spots and margins.

AUSTRIA, Kärnten, St. Margareten im Rosental, shrubs in front of the Stariwald, grid square 9452/4, on branches of Quercus petraea, 9 Jan. 1995, W. Jaklitsch W.J. 443 (WU 37034); same area, 31 Dec. 1997, W. Jaklitsch W.J. 1122 (WU 37035); Niederösterreich, Hagenbrunn, Bisamberg east side, grid square 7664/3, on twigs of Quercus petraea, 30 Oct. 1999, W. Jaklitsch W.J. 1396 (WU 37036); Mannersdorf am Leithagebirge, on twigs of Quercus petraea, 12 Mar. 2016, H. Voglmayr (specimen lost); Mühlleiten, Herrnau, on branches of Quercus petraea, 29 Mar. 2015, H. Voglmayr (WU 37037; culture CBS 145800 = D105); Oberösterreich, Unterach am Attersee, Stockwinkl, Egelsee, grid square 8147/3, on branch of Quercus petraea, 25 May 1996, W. Jaklitsch W.J. 880 (WU 37038); Steiermark, Wundschuh, Kaiserwald, at the Seerestaurant, grid square 9058/4, on branch of Quercus petraea, 10 Sep. 2002, W. Jaklitsch W.J. 1936 (BPI 843342; culture A.R. 3874); Vienna, 19^th district, at the Cobenzl, grid square 7763/2, on branches of Quercus cerris, 11 Feb 1995, W. Jaklitsch W.J. 482 (WU 37039); same area and host, 27 Feb. 1999, W. Jaklitsch W.J. 1286 (WU 37040). POLAND, E Grajewo, Kuligi, on branches of Quercus robur, 28 July 2015, H. Voglmayr (WU 37041; culture D144).

Asexual fructifications of this species are reported to have dimorphic conidia (Butin 1980; Wehmeyer 1933). However, for the description above only overmature material with a single type of conidia was available, the measurements of which agree with the cylindrical form given as 7–12 × 1.5–2 µm by Wehmeyer (1933), but their shape is more variable, possibly due to their age. As Butin (1980) observed, the asexual morph precedes the sexual morph and may still be present as separate acervuli among sexual pseudostromata or as locules within the periphery of the latter.

Figure 9. 

Dendrostoma leiphaemia. a–s Sexual morph a–e ectostromatic discs and ostioles f pseudostroma in cross section g pseudostroma in vertical section h peridium in cross section i, n–s ascospores j–m asci t–z asexual morph t conidioma in cross section u, v phialides w–z conidia; a, d–g, t–z WU 37037 (D105), b WU 37036 c, h, j, k, n WU 37038 i, l, m, p–s Mannersdorf o WU 37040. h, j, k, n, o, u–z In 3% KOH. Scale bars: 500 µm (a–g, t), 20 µm (h), 10 µm (j–m), 5 µm (i, n–s, u), 3 µm (v–z).