Sporisorium anadelphiae-leptocomae T. Denchev, Denchev, Kemler, M.P. Martín & Begerow, sp. nov.

Index Fungorum number: IF 558175; MycoBank number: MB 558175; Facesoffungi number: FoF 09652; Fig. 1.

Etymology – The specific epithet refers to the host species.

Holotype – SOMF 30250

Parasitic on Anadelphia leptocoma. Infection systemic. Sori destroying the racemes, 5–10 mm long, fusiform, all racemes of an infected plant affected; initially covered by a thick, yellow–brown peridium which later ruptures irregularly, exposing a single columella, surrounded by a powdery, dark reddish-brown mass of spores and sterile cells. Columella shorter than the sorus, flagelliform, apically slightly branched, sometimes slightly flattened or with shallow longitudinal furrows. Sori at first completely enclosed by the spatheoles, later more or less visible. Sterile cells firmly packed in irregular groups, collapsed, 9–14(–17) μm long, usually larger than the spores, hyaline to pale yellow; wall 0.6–1.0 μm thick. In SEM, smooth, sometimes partially rugulose. Spores subglobose, slightly irregular, broadly ellipsoidal, ellipsoidal or ovoid, (6.5–)7.5–9.5(–1 0.5)×(6–)7–8.5(–9.5) (8.6±0.6×7.8±0.6) μm (n=300), medium reddish brown; wall evenly thickened, 0.5–0.7 μm thick, smooth. In SEM, minutely echinulate-verruculose, ornaments up to 0.2 μm high, densely punctate between the main ornaments.

Material examined – Burkina Faso, Cascades Region, Léraba Province, Sindou Department, Tourni, dam, riverbed with seeping water, fallow fields, 10°46′ N, 05°09′ W, alt. 200–500 m, on Anadelphia leptocoma (Trin.) Pilg. (Poaceae), 28 October 1997, S. Lægaard, H. Mipro & T. Soberé, no. 18421 (SOMF 30250, holotype; MA 690545, isotype).

GenBank numbers – MW599285(ITS), MW599284 (LSU).

Notes – Anadelphia Hack. is a small genus of Poaceae Barnhart, tribe Andropogoneae Dumort., subtribe Andropogoninae J. Presl (including 514 species in 25 genera) (Soreng et al. 2017). Anadelphia comprises 14 species (Clayton et al. 2015) characterized by compound inflorescence composed of racemes. Anadelphia leptocoma is distributed in Tropical Africa (from Senegal to Zambia), mainly in West Tropical Africa (Clayton et al. 2015; Poilecot et al. 2015; Ibrahim et al. 2018). It is a characteristic grass of the savannahs (Poilecot et al. 2015).

Figure 1 –  Sporisorium anadelphiae-leptocomae (SOMF 30250, holotype). a, b Habit (black arrows in a and b show sori). c Spores in LM. d Spores and sterile cells in LM. e–h Spores in SEM. i Spores and sterile cells in SEM. Scale bars: a, b=0.5 cm, c, d=10 μm, e–i=5 μm