Dothideales » Saccotheciaceae » Saccothecium

Saccothecium sepincola

Saccothecium sepincola (Fr.) Fr. [as 'saepincola'], Summa veg. Scand., Sectio Post. (Stockholm): 398 (1849).

≡ Sphaeria sepincola Fr. [as 'saepincola'], Observ. mycol. (Havniae) 1: 181 (1815).

Index Fungorum number: IF 119497; Facesoffungi number: FoF 00108, Fig. 1

Description:

Saprobic on twigs. Sexual morph: Ascomata 135–140 μm diam. 100–125 μm high, black, immersed to semi-immersed, solitary or scattered, globose to subglobose, typically uniloculate, without a distinct ostiole. Peridium 18–20 μm wide, a single layer, composed of brown to lightly pigmented cells of textura angularis, near the base connected to the host tissue. Hamathecium lacking pseudoparaphyses. Asci 48−50 × 13−14 µm (x̄ = 49.6 × 13.1 µm, n = 10), 8-spored, bitunicate, fissitunicate, saccate to broadly clavate or oblong clavate, slightly curved, sessile or with a short bifurcate pedicel thickened at the apex with a distinct ocular chamber. Ascospores 13.5−18.3 × 4.2−5.9 µm (x̄ = 15.1 × 5.0 µm, n = 10), overlapping biseriate, hyaline, 3–6-septate, sometimes with 1 vertical septum, asymmetric, obovoid, fusiform to fusoid-ellipsoid, with broadly to narrowly rounded ends, broad upper cells, smooth-walled, not constricted at the septa. Asexual morph: Unknown.

Material examined: Italy, province of Forlì-Cesena [FC], Collinaccia - Castrocaro eTerra del Sole, on the twigs of Cornus sanguinea (Cornaceae), 3 March 2013, Erio Camporesi (MFLU 14–0276, epitype designated here).

Fig. 1 Saccothecium sepincola (MFLU 14–0276). a–d Herbarium material and appearance of ascomata on the host surface. e Section through ascomata. f Peridium. g–i Asci. j Hamathecium lacking pseudoparaphyses. k–o Ascospores. Scale bars: d = 500 μm, e = 50 μm, f–i = 20 μm, j, k–o = 10 μm.

Importance and distribution

Saccothecium species are parasitic or saprobic on plant hosts. Although there are 17 Saccothecium epithets in Index Fungorum (2022), several species have been transferred to other genera such as Buergenerula, Dothiora, Leptosphaeria, Leptosphaerulina and Wettsteinina. Saccothecium consists of nine species known on numerous host plants such as Acacia melanoxylon (Fabaceae), Ailanthus excels (Simaroubaceae), Amaranthus spinosus (Amaranthaceae), Amygdalus scoparia (Rosaceae), Artocarpus integra (Moraceae), Aruncus sylvestris (Rosaceae), Celastrus paniculatus (Celastraceae), Cestrum nocturnum (Solanaceae), Cornus kousa (Cornaceae), Crossandra undulifolia (Acanthaceae), Crotalaria medicaginea (Fabaceae), Cynodon dactylon (Poaceae), Dendrocalamus sp. (Poaceae), Eichhornia crassipes (Pontederiaceae), Hippophae rhamnoides (Elaeagnaceae), Laurus nobilis (Lauraceae), Paracaryum coelestinum (Boraginaceae), Philadelphus sp. (Hydrangeaceae), Phoenix paludosa (Arecaceae), Ribes nigrum (Grossulariaceae), Rosa canina (Rosaceae), Rubus fruticosus (Rosaceae) and Syzygium cumini (Myrtaceae). Saccothecium has a wide geographical distribution including Asia (India, Iran, Italy, Korea, Myanmar), Europe (Austria, Poland, Sweden, Germany), South America (Venezuela) and the United States. New collections of Saccothecium are needed as only two species have molecular data.