Cintractia mitchellii Vánky

Description

Sori occupying entire spikelets and developing from their basal part, at first covered by a whitish peridium of fungal origin and remnants of host tissues. Peridium rupturing early, flaking away to reveal black agglutinated globose to ovoid spore masses with a powdery surface, 1–3 mm long and 1–2 mm diam.; only a few spikelets of an inflorescence affected.

Spores slightly flattened, subcircular in plane view, broadly elliptic to slightly irregular, 9.5–13.5 × (10.0–) 11.0–14.5 µm, in side view 6.5–9.0 µm thick, medium reddish brown; wall uniformly c. 1 µm thick, in LM very finely and densely punctate-verruculose (not affecting the spore profile), in SEM finely and irregularly verrucose-reticulate.

Spore germination resulting in 4-celled basidia, 25–32 (–36) × 4.0–5.5 µm. Basidial cells fusing in pairs and giving rise to ovoid-elongate or subcylindrical basidiospores 20–30 (–40) × 3–4 µm, or to long 1.5–2.0 µm wide hyphae.

Hosts
   
Host family: Cyperaceae
   
Host species: Abildgaardia ovata (Burm.f.) Kral
Fimbristylis acuminata Vahl
Fimbristylis cardiocarpa F.Muell.
Fimbristylis furva R.Br.
Fimbristylis lanceolata C.B.Clarke
Fimbristylis littoralis Gaudich.
Fimbristylis nuda Boeck.
Fimbristylis pallida S.T.Blake
Fimbristylis phaeoleuca S.T.Blake
Fimbristylis rara R.Br.
Fimbristylis recta F.M.Bailey
Fimbristylis schultzii Boeck.
Fimbristylis solidifolia F. Muell.
Fimbristylis sphaerocephala Benth.
Fimbristylis squarrulosa F.Muell.
Fimbristylis tetragona R.Br.
Fimbristylis trigastrocarya F.Muell.

Distribution

States & Territories: NT, QLD, WA

Comments

Most collections have been made since 1997 when C. mitchellii was recognised as being distinct from C. axicola and Pilocintractia fimbristylidicola.