Microbotryum calyptratae Vánky

Description

Sori in swollen deformed flowers, restricted to the young capsules or also comprising the two sepals, but not extending to the floral pedicels, resembling a tulip flower in shape, 2–3 mm diam., at first covered by remnants of floral envelopes and a thin membrane of the capsule which ruptures irregularly exposing the dark purplish brown dusty mass of spores.

Spores subglobose, ovoid, ellipsoidal to slightly irregular, 13–19 × 12–16 µm, purplish brown, finely reticulate, with 6–10 (–11) polygonal meshes per spore diameter; interspaces with several small warts; muri in median view appearing as 1.5–2.5 µm high projections with a flattened top.

Spore germination resulting in slender basidia, to 4-septate, 80–90 µm long, on which basidiospores are produced laterally and terminally.

Hosts
   
Host family: Portulacaceae
   
Host species: Calandrinia calyptrata Hook.f.
Calandrinia volubilis Benth.

Distribution

States & Territories: SA, VIC

Comments

Microbotryum calyptratae differs from M. calandriniae (G.P.Clinton) Vánky (type on Calandrinia breweri Watson, USA), which does not occur in Australia, by the position of the sori and the dimensions of the muri. In the latter sori are restricted to the seeds, and the blunt muri are 2.5–4.0 (–5.0) µm high (Vánky, 1998).