Restiosporium sphacelatum Vánky

Description

Sori inconspicuous, c. 0.7 mm long and 1 mm wide, completely hidden by the floral envelopes, filling the capsules with a black initially agglutinated, later granular-powdery mass of spore balls. Infection systemic; all capsules of a plant affected.

Spore balls subglobose, ovoid, ellipsoidal, elongate to slightly irregular, 40–100 (–110) × 30–80 (–90) µm, dark reddish brown, composed of tens to 100(?) spores that separate by strong pressure.

Spores subglobose, ovoid, ellipsoidal to subpolyhedrally irregular, 9.0–14.5 (–16) × 8–11 µm, uniformly medium dark olivaceous brown; wall uniformly c. 0.5 µm thick; in LM smooth, in SEM free surface rough, very finely and densely low-verruculose.

Hosts
   
Host family: Restionaceae
   
Host species: Chordifex sphacelatus (R.Br.) B.G.Briggs & L.A.S.Johnson
Chordifex sinuosus B.G.Briggs & L.A.S.Johnson

Distribution

States & Territories: WA

Comments

Restiosporium sphacelatum and R. hypolaenae (on Hypolaena) were collected from the same area, but they differ in spore ball and spore morphology. Spore wall thickness and spore colour are uniform in R. sphacelatum but they vary in R. hypolaenae. There are also comparatively minor differences in the dimensions of spore balls and spores and in the degree of coherence of the spore balls (see above).