Sporisorium warambiense M. Piatek & R.G. Shivas
Sori in the ovaries, cylindrical, approx. 4 mm long and
2–3 mm wide, partly hidden by the floral envelopes
(glumes), initially covered by a leathery, pale brown
peridium which during maturity ruptures from the apex,
exposing a dark brown, semi-agglutinated to powdery mass
of spore balls surrounding three simple, stout, narrowing
columellae; columellae somewhat shorter than the length of
Spore balls dark reddish-brown, under pressure
readily disintegrating into single spores, subglobose, ellipsoidal
and somewhat irregularly polyhedral, 58–90 × 50–70 µm, composed of tens of spores.
ellipsoidal to irregular, usually more or less polyhedral,
(9.5–)10–13(–14) × 9–11(–12.5) µm (av. ± SD, 11.7±1.2 ×
10.2±0.9 µm), dimorphic; outer spores reddish-brown, wall
even, approx. 0.5–1.0 µm thick, prominently densely
verruculose in LM and SEM, especially on the free surface,
spore profile wavy to finely serrulate; inner spores
yellowish-brown, wall even, approx. 0.5 µm thick, moderately
finely punctate in LM, finely verruculose in SEM,
spore profile almost smooth.
Sterile cells absent.
||Xerochloa laniflora Benth.
States & Territories: WA
Sporisorium warambiense is very similar to S. xerofaciculatum, which also oocurs on Xerochloa in Western Australia. It differs in that S. xerofasciculatum has sterile cells and smaller spores that are less densely verruculose. Further collections will help determine if these differences warrant separation of these taxa or whether it merely indicates variation in a single species.