Tilletia lachnagrostidis Vánky & R.G. Shivas

Description

Sori in all ovaries of an inflorescence, lemon-shaped or ellipsoidal with an acute tip, 1.0–1.5 mm long, 0.5–0.8 mm wide, partly hidden by the floral envelopes, at first covered by the thin pericarp that ruptures irregularly exposing the pale brown semi-agglutinated to powdery mass of spores and sterile cells.

Spores globose, subglobose to broadly ellipsoidal, 18.5–23.0 × 17.5–21.0 µm, pale yellowish brown, with 2.5–3.5 (–4.0) µm high subconical warts; in surface view appearing as darker rounded or irregular spots, 3–5 per spore diameter, connected by numerous darker narrow lines, sometimes 2 or 3 spots fused; in optical median view with 16–20 warts on the equatorial circumference, embedded in a hyaline sheath.

Sterile cells subglobose, ellipsoidal or irregular, 9–17 × 8.0–13.5 µm, hyaline; wall 0.5–1.5 µm thick, smooth; larger subhyaline intermediate cells with traces of surface ornamentation.

Spore germination by means of an aseptate basidium with an apical whorl of about 30 acicular basidiospores measuring (30–) 50–65 × 1.0 µm.

Hosts
   
Host family: Poaceae
   
Host species: Lachnagrostis filiformis (G.Forst.) Trin.

Distribution

States & Territories: NSW

Comments

This species is similar to T. pallida G.W.Fisch. (type on Agrostis palustris Hudson, U.S.A.) which has not been reported in Australia. However, T. pallida has spores that are coarsely echinulate, with 21–35 spines on the equatorial circumference which are not connected by fine lines in surface view.