Restiosporium chaetanthi Vánky

Description

Sori filling the nuts with a black initially agglutinated, but finally granular-powdery mass of spore balls, inconspicuous, hidden by the somewhat spreading floral envelopes. Infection systemic; all capsules of a plant infected.

Spore balls globose, ovoid, ellipsoidal or elongate, 40–90 (–100) × 35–70 µm, yellowish to dark olivaceous brown, composed of tens of spores that separate by pressure.

Spores subpolyhedrally or polyhedrally irregular, often with subacute or acute points and also lines between 2 flattened sides, 9–13 (–14.5) × 7–11 µm, olivaceous brown; wall slightly uneven, 0.5–1.0 µm thick, thickest at the angles; in LM smooth, in SEM the free surface very finely and densely low-verruculose.

Hosts
   
Host family: Restionaceae
   
Host species: Chaetanthus aristatus (R.Br.) B.G.Briggs & L.A.S.Johnson

Distribution

States & Territories: WA