Chaetoscutula juniperi E. Müll., Sydowia 12(1–6): 191 (1959) [1958]

Index Fungorum number: IF 294737; MycoBank number: MB 294737; Facesoffungi number: FoF 03694; Fig. 1

Saprobic on leaves of Juniperus spp. Sexual morph: Ascomata growing in the contact zone between two adjacent leaves, solitary or gregarious, superficial, hemispherical, 146–200 μm diam. (x̅=179 μm, n=5), dark brown to black, and always ornamented with more or less dense, long and gnarled setae, 80–128×3.5–4.4 μm (x̅=99×3.9 μm, n=8) and with a thickened wall up to 2 μm. Shorter, lighter and blunt developing setae interspersed among the former. Peridium thin of dark brown, 4–9 μm wide, thick-walled cells of textura angularis. Ostiole inconspicuous. Hamathecium not distinguishable, but hyaline gelatinous matrix is discernible among asci. Asci 50–84×20–30 μm (x̅=66×25 μm, n=7), 8-spored, bitunicate, arranged in parallel and originating from a basal layer of hyaline, subcylindrical, broadly ellipsoid to obpyriform, loosely interwoven hyphae. Ascospores 23–28 μm long (x̅=25.5 μm, n=10), cylindrical to clavate, 1-septate, constricted at the septum, heteropolar, smaller cell width of 8.3–10.8 μm (x̅= 9.6 μm, n = 10), larger cell width of 9.7–11.5 μm (x̅=10.5 μm, n=10), rounded at both extremes, first hyaline and then slightly brownish when mature, not surrounded by a distinct gelatinous sheath. Asexual morph: Undetermined.

Material examined – SPAIN, Comunitat Valenciana, Valencia Province, Racó d’Ademús, Vallanca, on leaves of Juniperus phoenicea growing along the Bohílgues River margin, 40°3′50.08″ N 1°20′50.88″ W, 958 msl, 19 August 2019, I. Garrido-Benavent, IGB756 (Real Jardín Botánico herbarium, MA-90552); Alacant Province, Vall d’Ebo, Corrals de Pego, entrance to the Barranc de l’Infern, on leaves of J. phoenicea, 38°48′23.59″ N 0°08′23.41″ W, 377 msl, 29 December 2019, I. Garrido-Benavent, IGB857 (MA-92235); Castelló Province, Vistabella del Maestrat, between Alt de l’Asevar and El Chaparral, on leaves of J. sabina in a forest of Pinus sylvestris, 40°15′55.94″ N 0°22′57.52″ W, 1624 msl, 21 August 2014, I. Garrido-Benavent, IGB793 (MA90553); Pina de Montalgrao, on leaves of J. phoenicea, 40°01′16.47″ N 0°39′24.86″ W, 1034 msl, 21 August 2014, I. Garrido-Benavent, IGB794 (MA-90554); Castilla y León, Soria Province, Abejar, Sierra de Cabrejas, road to Calatañazor, on leaves of J. thurifera, 41°46′37.50″ N 2°46′41.20″ W, 1161 msl, 17 March 2014, I. Garrido-Benavent, IGB795 (MA-90641); Aragón, Teruel Province, La Puebla de Valverde, Corral de la Ceja, on leaves of J. sabina, 40°12′41.65″ N 0°57′36.61″ W, 1276 msl, 17 March 2014, I. GarridoBenavent, IGB796 (MA-90556); Castilla-La Mancha, Albacete Province, Férez, Montes de Aguas Calientes, on leaves of J. phoenicea, 38°25′24.82″ N 1°52′40.46″ W, 501 msl, 27 December 2019, I. Garrido-Benavent, IGB835 (MA-92233); Murcia, Moratalla, between Benízar and Casicas del Portal, on leaves of J. phoenicea, 38°14′49.05″ N 1°59′59.85″ W, 1170 msl, 27 December 2019, I. GarridoBenavent, IGB845 (MA-92234); Ibidem, El Sabinar, close to Cortijo de la Leona, road to Letur, on leaves of J. thurifera, 38°13′01.38″ N 2°08′07.61″ W, 1194 msl, I. GarridoBenavent, IGB842.

GenBank numbers – ITS=MN756704, LSU=MN756705, SSU=MN756706 (all sequences obtained from the voucher MA-90552).

Notes – The morphological description of Iberian Chaetoscutula juniperi (Fig. 1) specimens that we provide here is in the agreement with the original species description (Müller 1958). There are, however, subtle differences in the size of setae and spores, which in our specimens tend to be slightly larger than previously described. Tian et al. (2014) provided the second and most recent description of the species based on material collected by E. Müller in France (collection S-F225899). Although the authors claimed that the studied ascomata “sometimes” displayed setae, the ascomata represented in the photographic plate (Tian et al. 2014; Fig. 2d) and the associated text description do not seem to match well with the concept of C. juniperi. Either in the present description or the one provided in the original publication (Müller 1958), C. juniperi has always been characterized as forming setae on the surface of ascomata; besides, ascomata were described as hemispherical, whereas Tian et al. (2014) described it as globose to subglobose and with much smaller ascomata (see Tian et al. 2014; Fig. 2e, f). A reevaluation of the collection S-F225899 must be conducted to ascertain whether it corresponds to the true C. juniperi or to other species growing on the same substrate (Juniperus leaves) such as Pododimeria gallica and Seynesiella juniperi, which share some microscopic characters with C. juniperi and cooccurred in the type collection (ZT Myc 60709).

Figure 1 –  Chaetoscutula juniperi (MA-90552, new record). a–d Ascomata on leaves of Juniperus phoenicea. e, f Ascomata immersed in water showing their hemispherical shape and their surface with dense, long and gnarled setae. g Peridium cells in surface view. h, n, o Setae. i, j, p Asci in several developmental stages. k–m, q, r Ascospores in several developmental stages. Scale bars: a– d=0.5 mm, e, f=50 µm, g–r=10 µm

Figure 2 –  Diplodia alanphillipsii (IRAN 14273F, holotype). a Conidiomata on pine needles in culture. b Hyaline immature conidia developing on conidiogenous cells. c, d Conidiogenous cells with periclinal thickenings or annellations. e Brown aseptate conidia on conidiogenous cells. f Mature brown conidia. g, h Mature conidia in two different focal planes. Scale bars: a=500 μm, b–f=5 μm, g, h=10 μm