Juglanconis Voglmayr & Jaklitsch, Persoonia 38: 142 (2017)

Juglanconidaceae, with the single genus Juglanconis, was newly introduced by Voglmayr et al. (2017) for Melanconium juglandinum, M. oblongum and M. pterocaryae. In this paper, we provide an updated tree including accessions of two Juglanconis species from China (Fig. 2).

Juglanconis juglandina (Kunze) Voglmayr & Jaklitsch, Persoonia 38: 144 (2017).

Juglanconis was newly introduced by Voglmayr et al. (2017). The genus is characterised by having perithecial ascomata, octosporous asci with an apical ring, hyaline, bicellular ascospores with or without gelatinous appendages and acervular conidiomata with brown conidia with gelatinous sheaths and with verruculous inner surface of the conidal wall (Voglmayr et al. 2017). Juglanconis includes four species (J. appendiculata, J. juglandina, J. oblonga and J. pterocariae), which were restricted to host in Juglandaceae (Voglmayr et al. 2017).

Conidiomata acervular, immersed in host bark, erumpent from surface of host branches, scattered or occasionally confluent, 1.5–2.5 mm, covered by black discharged conidial masses at maturity, usually conspicuous. Ectostromatic disc straw to honey, surrounded by bark or not. Central column beneath the disc more or less conical, straw to buff. Conidiophores cylindrical to lageniform, simple, rarely branched at the base, smooth, subhyaline to pale brown. Conidiogenous cells annellidic with distinct annellations, integrated. Conidia unicellular, initially hyaline, becoming brown to blackish when mature, broadly ellipsoid to broadly pip-shaped, truncate with distinct scar at the base, densely multiguttulate, thick-walled, (17–)19–22(–24.5) × (9–)11–14(–16.5) μm (av. = 20 × 13 μm, n = 50), with 0.8–1 µm wide gelatinous sheath. Sexual morph was not observed.

Figure 3. 

Morphology of Juglanconis juglandina from Juglans regia. A–B habit of acervuli on branches C transverse section through acervulus D longitudinal section through acervulus E–F conidiophores, conidiogenous cells and conidia. Scale bars: 1 mm (A–D), 20 μm (E–F).

On PDA, cultures are initially white, becoming straw after 3–5 d and grey olivaceous after 7–10 d. The colonies are felty with an irregular edge; sterile.

(all on twigs and branches of Juglans regia). CHINA, Gansu Province, Qingyang City, Shishe village, 35°38'17.08"N, 107°47'48.68"E, 14 July 2013, X.L. Fan (BJFC-S908; living culture, CFCC 51727); Gansu Province, Qingyang City, Zhongwan Forest Farm, 35°26'26.33"N, 108°34'09.38"E, 11 July 2013, X.L. Fan (BJFC-S947; living culture, CFCC 51728); Gansu Province, Qingyang City, Zhongwan Forest Farm, 35°26'25.52"N, 108°34'09.03"E, 11 July 2013, X.L. Fan (BJFC-S955; living culture, CFCC 51729).

Juglanconis juglandina is the type species of Juglanconis and is thus far only known to occur on Juglans regia distributed in Asia and Europe (Voglmayr et al. 2017). Juglanconis juglandina is described based on Melanconium juglandinum (= Melanconis carthusiana) (Voglmayr et al. 2017), which was regarded as the main causal agent of canker and dieback disease of Juglans regia in China (China Microbiology and Virology Databases, http://www.micro.csdb.cn/).

Pseudostromata immersed in host bark, distinctly erumpent from surface of host branches, 1.5–3 mm diam. Ectostromatic disc indistinct, usually circular, greyish to brownish. Perithecia often appearing as rounded bumps beneath the bark surface surrounding the ectostromatic disc, prolonged black neck from the top, (450–)525–700(–780) µm diam. (av. = 580 μm, n = 30). Asci hyaline, clavate to fusoid, (120–)122–135 × (12.5–)13–16.5 (–17) μm (av. = 126.5 × 15 μm, n = 20). Ascospores hyaline, ellipsoid, broadly ellipsoid or broadly fusoid, symmetric to slightly asymmetric, straight, rarely slightly curved, constricted at the septum, (17–)17.5–22(–23.5) × (7.5–)8–10.5(–11) μm (av. = 19.5 × 9.5 μm, n = 50). Conidiomata acervular, immersed in host bark, erumpent from surface of host branches, scattered or occasionally confluent, 1–2 mm, covered by black discharged conidial masses at maturity, usually conspicuous. Ectostromatic disc buff to honey, surrounded by bark or not. Central column beneath the disc more or less conical, isabelline to olivaceous grey. Conidiophores cylindrical to lageniform, simple, rarely branched at the base, smooth, subhyaline to pale brown. Conidiogenous cells annellidic with distinct annellations, integrated. Conidia unicellular, initially hyaline, becoming brown to blackish when mature, broadly ellipsoid to broadly pip-shaped, truncate with distinct scar at the base, densely multiguttulate, thick-walled, (14–)19–23.5(–28) × (6.5–)9–13(–15) μm (av. = 22 × 12.5 μm, n = 50), with 0.8–1 µm wide gelatinous sheath.

Figure 4. 

Morphology of Juglanconis oblonga from Juglans regia. A–B habit of acervuli on branches C transverse section through acervulus D longitudinal section through perithecia E longitudinal section through acervulus F conidiophores, conidiogenous cells G conidia H asci and ascospores I ascospores. Scale bars: 10 mm (A), 500 μm (B–E), 20 μm (F–I).

On PDA, cultures are initially white, becoming pale olivaceous grey after 10 d. The colonies are felty with an irregular edge; texture uniform; sterile.

(all on twigs and branches of Juglans regia). CHINA, Heilongjiang Province, Harbin City, Linan, Heilongjiang Botanical Garden, 45°42'21.10"N, 126°38'42.87"E, 2 August 2016, Q. Yang & Z. Du (BJFC-S1374; living culture, CFCC 51725; ibid.CFCC 51726).

Juglanconis oblonga is based on Melanconium oblongum (= Melanconis juglandis) (Voglmayr et al. 2017). This species can be distinguished from J. juglandina by on average longer length of conidia (22 × 12.5 vs.> 20 × 13 µm). However, there is a substantial size overlap between both species and sequence data are sometimes necessary for reliable species identification. It was also recorded to cause canker and dieback disease of Juglans regia in China (China Microbiology and Virology Databases, http://www.micro.csdb.cn/).

Melanconis Tul. & C. Tul., Select. fung. carpol. (Paris) 2: 115 (1863)

Melanconidaceae was introduced by Winter (1886) and subsequently involved many genera with perithecia immersed in a well-developed stroma with ostioles (beaks) that emerge through an ectostromatic disc (Barr 1978). Castlebury et al. (2002) and Rossman et al. (2007) reduced this family to the type genus Melanconis based on LSU rDNA sequences. In this paper, we provide an updated tree with additional isolates of Melanconis (Melanconidaceae) from China (Fig. 5). All species have been described and illustrated by Fan et al. (2016).

Figure 5. 

Phylogram of Melanconis (Melanconidaceae) obtained from an MP analysis of a combined matrix of ITS, LSU, RPB2 and TEF1-α. MP and ML bootstrap support values above 50% are shown at the first and second position, respectively. Thickened branches represent posterior probabilities above 0.95 from BI. Scale bar = 20 changes. Type species are in bold. Strains obtained in the current study are in blue.

Melanconis stilbostoma (Fr.) Tul. & C. Tul., Select. fung. carpol. (Paris) 2: 115 (1863)

The type genus Melanconis was established by Tulasne and Tulasne (1863) based on Sphaeria stilbostoma Fr. This genus is characterised by circularly arranged perithecia immersed in well developed to reduced entostromata with a concolourous central column and ostioles erumpent through a light-coloured ectostromatic disc with hyaline, one-septate ascospores; acervuli with light-coloured central column producing brown to olive-brown, fusiform to pyriform alpha conidia and hyaline, cylindrical or allantoid beta conidia (Barr 1978; Castlebury et al. 2002; Voglmayr et al. 2012; Fan et al. 2016). Melanconis has approximately 105 species epithets recorded in Index Fungorum (2018), whereas Rossman et al. (2007) suggested that many of the species previously residing in Melanconis may belong somewhere else. Fan et al. (2016) provided an account on this genus including five species (Melanconis alni, Ms. betulae, Ms. marginalis, Ms. itoana and the type species Ms. stilbostoma), which were restricted to hosts in Betulaceae.

(all on twigs and branches of Betula albosinensis). CHINA, Gansu Province, Gannan Tibetan Autonomous Prefecture, Zhouqu County, Qiban Forestry Centre, 33°56'35.36"N, 104°07'13.03"E, 20 August 2014, Y.M. Liang (BJFC-S1319, holotype; living ex-type culture, CFCC 50471); Gansu Province, Gannan Tibetan Autonomous Prefecture, Zhouqu County, Qiban Forestry Centre, 33°56'37.05"N, 104°07'13.78"E, 20 August 2014, Y.M. Liang (BJFC-S13200; living culture, CFCC 50472); Gansu Province, Gannan Tibetan Autonomous Prefecture, Zhouqu County, Qiban Forestry Centre, 33°56'34.44"N, 104°07'15.59"E, 20 August 2014, Y.M. Liang (BJFC-S1321; living culture, CFCC 50473).

Melanconis betulae was described from Betula albosinensis (Fan et al. 2016). Morphologically, M. betulae is characterised by ovoid, olive-brown, aseptate alpha conidia, which are different from other Melanconis species but similar to the type species Ms. stilbostoma. However, it can be distinguished by the smaller length of its alpha conidia (10 vs.> 12 μm) and sequence data.

(all on twigs and branches of Betula albosinensis). CHINA, Gansu Province, Gannan Tibetan Autonomous Prefecture, Zhouqu County, Qiban Forestry Centre, 33°56'34.49"N, 104°07'15.21"E, 20 August 2014, X.L. Fan (BJFC-S1322; living culture, CFCC 50474); Shaanxi Province, Ankang City, Ningshan County, Huoditang Forest Farm, 33°26'24.80"N, 108°26'45.10"E, 3 August 2015, Q. Yang (BJFC-S1349; living culture, CFCC 52877; ibid, CFCC 52878); Jilin Province, Jiaohe City, Haiqing Forest Farm, 43°79'88.71"N, 127°15'83.04"E, 26 June 2017, X.W. Wang (CF 20170668; living culture, CFCC 52876).

Melanconis itoana was described from Betula ermanii in Japan (Kobayashi 1970). Fan et al. (2016) isolated it from Betula albosinensis as a new record in China. Melanconis itoana is characterised by fusoid, green-brown alpha conidia with acute ends (13 × 4 μm) and hyaline, cylindrical or crescent beta conidia (9.5 × 1.5 μm).

(all on twigs and branches of Betula platyphylla). CHINA, Tibet Autonomous Region, Linzhi City, Juemu Valley, 29°39'50.13"N, 94°18'50.70"E, 22 July 2016, X.L. Fan (CF 20160703; living culture, CFCC 528433); Heilongjiang Province, Yichun City, Dailing District, Liangshui Natural Reserve, 47°11'05.26"N, 128°57'26.15"E, 29 July 2016, Q. Yang & Z. Du (CF 20161703; living culture, CFCC 52867); Heilongjiang Province, Harbin City, Heilongjiang Botanical Garden, 45°42'27.58"N, 126°38'36.72"E, 2 August 2016, Q. Yang & Z. Du (CF 20161709; living culture, CFCC 52868); Qinghai Province, Menyuan City, Xianmi Forest Farm, 37°16'35.27"N, 101°46'53.78"E, 3 September 2016, J.H. Zuo (CF 20160911; living culture, CFCC 52865); Ningxia Autonomous Region, Yinchuan City, Helan County, Taihedizhonghai, 38°31'50.40"N, 106°17'46.10"E, 5 August 2015, X.L. Fan & Z. Du (CF 20150802; living culture, CFCC 52873); Ningxia Autonomous Region, Jingyuan City, Jingguan Road, 35°29'50.32"N, 106°18'27.10"E, 13 August 2014, X.L. Fan & Z. Du (BJFC-S1324; living culture, CFCC 50476); Beijing City, Tongzhou District, Song Village, 35°59'49.50"N, 116°39'32.35"E, 20 May 2015, X.L. Fan (BJFC-S1325; living culture, CFCC 50477); other materials with similar locations and hosts are listed in Table 1.

Melanconis stilbostoma is the type species of Melanconis and is thus far only known to occur on Betula spp. with a worldwide distribution (Fan et al. 2016). Betula pendula, B. rotundifolia and B. tianschanica are recorded as hosts in China (Zhuang 2005). The current investigation suggested that this species is restricted to and widespread on Betula platyphylla in China.

Melanconiella Sacc., Syll. fung. (Abellini) 1: 740 (1882)

Melanconiellaceae was validated by Senanayake et al. (2017) for the invalid Melanconiellaceae of Locquin (1984). Senanayake et al. (2017) emended this family to accommodate Dicarpella, Greeneria, Melanconiella, Microascospora and Tubakia. Braun et al. (2018) recommended an exclusion of Dicarpella, Greeneria and Tubakia. In this paper, we introduce the new genus Sheathospora and two new species of Melanconiella in Melanconiellaceae (Fig. 6).

Figure 6. 

Phylogram of Melanconiellaceae obtained from an MP analysis from a combined matrix of ITS, LSU, RPB2 and TEF1-α. MP and ML bootstrap support values above 50% are shown at the first and second position, respectively. Thickened branches represent posterior probabilities above 0.95 from BI. Scale bar = 80 changes. Type species are in bold. Strains obtained in the current study are in blue.

Melanconiella spodiaea (Tul. & C. Tul.) Sacc., Syll. fung. (Abellini) 1: 740 (1882)

The genus Melanconiella was established by Saccardo (1882) for two species, Melanconis spodiaea Tul. & C. Tul. and M. chrysostroma (Fr.) Tul. & C. Tul. The genus subsequently entered a long period of confusion with a broad concept of the melanconidaceous genera Melanconium and Melanconis Tul. & C. Tul. (Wehmeyer 1937, 1941; Barr 1987). Melanconiella has 37 species epithets recorded in Index Fungorum (2018). Voglmayr et al. (2012) revised the generic circumscriptions of Melanconiella with 13 accepted species, excluded numerous species and confirmed that it is genetically distinct from the genus Melanconis based on morphology and multi-gene phylogeny (ITS, LSU, RPB2 and TEF1-α). Melanconiella is characterised by forming circularly arranged perithecia immersed in the substrate with oblique or lateral ostioles convergent and erumpent through an ectostromatic disc with dark coloured or hyaline ascospores; acervuli with light-coloured central column, producing dark brown melanconium-like or hyaline discosporina-like conidia (not in the same species) (Barr 1978; Voglmayr et al. 2012). Melanconiella species were observed to be highly host-specific, as they were found to be confined to a single genus or sometimes even species within the host family Betulaceae from Europe and North America (Voglmayr et al. 2012).

betulicola (Lat.): referring to the host genus on which it was collected, Betula.

This species is distinguished by hyaline ascospores, (16.5–)18–22(–24) × (3–)4–6 μm, with slightly constricted at the septum and with hyaline broad cap-like appendages at both ends.

CHINA. Shaanxi Province: Ningshan County, Huoditang Forest Farm, Huodi Valley, 33°26'36.32"N, 108°26'46.48"E, 3 August 2015, on twigs and branches of Betula albosinensis, Q. Yang (BJFC-S1347 holotype; living culture, CFCC 52482).

Pseudostromata inconspicuous, immersed in host bark, slightly erumpent from surface of host branches, 1.5–3 mm diam. Ectostromatic disc indistinct, usually circular, buff to hazel. Central column circular, mouse grey to iron grey. Ostioles numerous, violaceous black to black, scarcely projecting, 70–150 μm diam. Perithecia flask-shaped to spherical, arranged circularly or irregularly, 7–12 per disc, often appearing as rounded bumps beneath the bark surface surrounding the ectostromatic disc, (320–)350–550(–610) µm diam. (av. = 480 μm, n = 30). Asci hyaline, clavate to fusoid, (50–)55–65(–70) × (7–)8.5–14(–16) μm (av. = 60 × 11 μm, n = 20). Ascospores hyaline, ellipsoid, broadly ellipsoid or broadly fusoid, 2–4 guttulate, symmetric to slightly asymmetric, straight, rarely slightly curved, slightly constricted at the septum, (16.5–)18–22(–24) × (3–)4–6 μm (av. = 20 × 4.5 μm, n = 50), with hyaline broad cap-like appendages at both ends. Conidiomata acervular, immersed in host bark, erumpent from surface of host branches, scattered or occasionally confluent, 1.3–2.5 mm, covered by fawn to dark brick discharged conidial masses at maturity, usually conspicuous. Ectostromatic disc inconspicuous. Central column beneath the disc more or less conical, olivaceous grey to iron grey. Conidiophores hyaline, smooth, cylindrical to lageniform, simple, rarely branched at the base. Conidiogenous cells hyaline, phialidic. Conidia unicellular, hyaline, narrowly ellipsoid, elongate to slightly allantoid, (9.5–)10–13.5(–15) × (2–)3–4.5(–5.5) μm (av. = 13 × 3.5 µm, n = 50), with 0.5 µm wide gelatinous sheath.

Figure 7. 

Morphology of Melanconiella betulicola from Betula albosinensis. A–B habit of pseudostromata on branches C transverse section through perithecia D longitudinal section through perithecia E–F habit of acervuli on branches G transverse section through acervulus H longitudinal section through acervulus I asci and ascospores J–K ascus and ascospores L–O ascospores P conidiophores, conidiogenous cells and conidia Q conidia. Scale bars: 2 mm (A, E), 500 μm (B–D, F–H), 10 μm (J–K, P–Q), 5 μm (L–O).

On PDA, cultures are initially white, becoming greyish-sepia after 3 d and distensible radially after 10 d. The colonies are felty with an irregular edge; texture uniform; sterile.

CHINA. Shaanxi Province: Ningshan County, Huoditang Forest Farm, Huodi Valley, 33°26'37.53"N, 108°26'44.14"E, 3 August 2015, on twigs and branches of Betula albosinensis, Q. Yang (CF 20150847; living culture, CFCC 52483);

Melanconiella betulicola is associated with canker disease of Betula albosinensis in China. It is similar to M. ellisii but differs by larger ascospores (18–22 × 4–6 vs.> 12.5–16 × 4.0–5.5 μm) with hyaline, broad cap-like appendages at both ends (Voglmayr et al. 2012), distribution (China vs.> eastern North America) and a different host, Betula albosinensis vs.> Carpinus caroliniana. Melanconiella decorahensis also occurs on Betula (in Europe and North America) and it can be distinguished from M. betulicola based on dark brown ascospores without appendages and dark brown conidia (Voglmayr et al. 2012). The clear phylogenetic position confirmed a distinction from all other available strains included in this study and we therefore result in our decision to describe this species as new, based on DNA sequence data and morphology.

corylina (Lat.): referring to the host genus on which it was collected, Corylus.

This species is distinguished by acervuli erumpent through circularly cracked host bark and covered by olivaceous buff to honey discharged conidial masses at maturity; conidia unicellular, hyaline, with various shapes and 1–3 guttulate, (7–)8–13.5(–14.5) × (2–)2.5–4(–5) μm.

Figure 8. 

Morphology of Melanconiella corylina from Corylus mandshurica. A habit of acervuli on branches B–F process of development of acervulus G transverse section through acervulus H–I longitudinal section through acervulus J conidiophores K conidiogenous cells and conidia L–W conidia. Scale bars: 2 mm (A), 500 μm (B–I), 10 μm (J–K), 5 μm (L–W).

CHINA. Shaanxi Province: Baoji County, Taibai Mountain, 34°15'43.32"N, 107°88'42.16"E, 13 July 2017, on twigs and branches of Corylus mandshurica, N. Jiang (BJFC-FB56 holotype; living culture, CFCC 52484).

Conidiomata acervular, immersed in host bark, erumpent from surface of host branches, scattered or occasionally confluent, 1–1.5 mm, erumpent through circularly cracked host bark and covered by olivaceous buff to honey discharged conidial masses at maturity, usually conspicuous. Ectostromatic disc inconspicuous and cracked circularly at maturity. Central column beneath the disc more or less oblate, iron grey to dark grey. Conidiophores hyaline, smooth, cylindrical, simple, rarely branched at the base. Conidiogenous cells hyaline, phialidic. Conidia unicellular, hyaline, narrowly ellipsoid to fusoid, elongate to slightly allantoid, 1–3 guttulate, (7–)8–13.5(–14.5) × (2–)2.5–4(–5) μm (av. = 10 × 3.5 µm, n = 50) μm (av. = 13 × 3.5 µm, n = 50). Sexual morph was not observed.

On PDA, cultures are initially white, becoming fuscous black in the centre and edge after 5 d. The colonies are felty with an irregular edge; texture uniform; sterile.

CHINA. Shaanxi Province: Baoji County, Taibai Mountain, 34°15'40.05"N, 107°88'43.33"E, 13 July 2017, on twigs and branches of Corylus mandshurica, N. Jiang (CF 20170756 holotype; living culture, CFCC 52485).

Melanconiella corylina is associated with canker disease of Corylus mandshurica in China. It can be distinguished from its closest relative, the generic type M. spodiaea growing in Carpinus spp., by its hyaline, discosporina-like conidia, and the smaller size of conidia (8–13.5 × 2.5–4 vs.> 13.3–15.2 × 7.5–8.5 μm) as well as the hosts (Voglmayr et al. 2012). Melanconiella flavovirens also occurs on Corylus (in Europe and North America), and it can be distinguished from M. corylina based on larger conidia (12–15 × 5.0–5.5 vs.> 8–13.5 ×2.5–4 μm) (Voglmayr et al. 2012). The phylogenetic inferences indicated M. corylina as an individual well-supported clade (MP/ML/BI=100/99/1) within Melanconiella and we therefore describe it as new, based on sequence data and morphology.

Sheathospora (Lat.): referring to the conidia with distinct hyaline sheath.

This genus differs from other genera in Melanconiellaceae by conical and discrete pycnidia with aseptate, cylindrical to ellipsoidal conidia with distinct hyaline sheath.

Sheathospora cornuta (C.M. Tian & Z. Du) Fan.

Conidiomata pycnidial, immersed in host bark, erumpent through the surface of host branches. Ectostromatic disc inconspicuous and extended to form a beak at maturity. Central column absent. Conidiophores hyaline, smooth, cylindrical, simple, rarely branched at the base. Conidiogenous cells hyaline, phialidic. Conidia hyaline, aseptate, with distinct hyaline sheath. Sexual morph was not observed.

Sheathospora is established for Melanconiella cornuta, which was previously included in the Melanconiella clade (Voglmayr et al. 2012; Du et al. 2017). Morphologically, it differs from other genera in Melanconiellaceae by pycnidial conidiomata and conidia with distinct hyaline sheath. In our phylogenetic analyses, Melanconiella cornuta formed a distinct clade basal to Melanconiella within Melanconiellaceae. Based on morphology and different hosts (Cornus and Juglans vs. Betulaceae), it is here excluded from Melanconiella and transferred to the new genus Sheathospora. In our revised circumscription, Melanconiellaceae include three genera named Melanconiella, Microascospora and Sheathospora.

Melanconiella cornuta C.M. Tian & Z. Du, Phytotaxa 327(3): 257 (2017)

This species is distinguished by conical and discrete pycnidia without central column and aseptate, cylindrical to ellipsoidal, (19–)19.5–22.5(–23) × (8–)8.5–10.5(–11) μm conidia, with a distinct hyaline sheath 1–1.5 μm wide.

CHINA. Shaanxi Province: Ankang City, Ningshan County, Huoditang Forest Farm, 33°26'04.46"N, 108°26'59.91"E, 3 July 2016, on twigs and branches of Cornus controversa, X.L. Fan (BJFC-S1375 holotype; living ex-type culture CFCC 51990).

Conidiomata pycnidial, immersed in host bark, conical, with single necks erumpent through the surface of host branches, scattered, (250–)270–330(–410) μm (av. = 300 μm, n = 20) diam. Ectostromatic disc inconspicuous and extended to form a beak at maturity, pale luteous to amber. Central column absent. Conidiophores hyaline, smooth, cylindrical, simple, rarely branched at the base, 17–24(–25) × 2.5–4(–4.5) μm (av. = 21.5 × 3.5 µm, n = 50). Conidiogenous cells hyaline, phialidic. Conidia hyaline, aseptate, cylindrical to ellipsoidal, (19–)19.5–22.5(–23) × (8–)8.5–10.5(–11) μm (av. = 21 × 10 µm, n = 50), with distinct hyaline sheath, 1–1.5 μm wide at maturity. Sexual morph was not observed.

Figure 9. 

Morphology of Sheathospora cornuta from Cornus controversa. A–B Habit of pycnidia on branches C–D transverse section through pycnidium E longitudinal section through pycnidium F conidiophores, conidiogenous cells G conidia. Scale bars: 5 mm (A), 1 mm (B), 500 μm (C–E), 20 μm (F–G).

Colony growth on PDA originally white, becoming pale yellowish after 7–10 days. Colony flat, felty-like, with a uniform texture and yellowish to dark brown conidiomata irregularly scattered on the colony surface.

CHINA. Shaanxi Province: Ankang City, Ningshan County, Huoditang Forest Farm, 36°26'13.30"N, 108°26'48.32"E, 3 August 2015, on twigs and branches of Juglans regia, Q. Yang (BJFC-S1345 paratype; living ex-paratype culture CFCC 51991).

Sheathospora cornuta is proposed here as a new combination for Melanconiella cornuta. It is the type and currently only species of Sheathospora and so far known from Cornus controversa and Juglans regia in China. The sexual morph of this species is unknown and further collections are required to elucidate its life cycle.