Cintractia Cornu

Type

Cintractia axicola (Berk.) Cornu on Fimbristylis dichotoma (L.) Vahl.

Description

Sori surrounding the floral axis of plants in the Cyperaceae, less often surrounding the ovaries, subglobose to cylindrical, at first covered by a white or brown sterile fungal peridium that flakes away to expose the blackish brown or black semi-agglutinated spore mass.

Spores solitary, more rarely in balls, dark, medium-sized, formed on a mycelial stroma.

Spore germination with phragmobasidia, the cells often conjugating.

Host-parasite interaction by intracellular hyphae coated by an electron-opaque matrix.

Septa poreless at maturity.

Comments

A genus of 12 species that infect host plants in the Cyperaceae. Seven species, including three endemics, have been reported from Australia. Begerow et al. (2006) used DNA molecular analyses to demonstrate that species of Anthracoidea, Cintractia, Dermatosorus, Farysia, Heterotolyposporium, Moreaua, Planetella, Schizonella, Stegocintractia, Tolyposporium and Trichocintractia formed a monophyletic clade. They considered that Ustilaginales parasitic on Cyperaceae and Juncaceae were best placed in the Anthracoideaceae. However, a comprehensive molecular study towards an internal classification of Ustilaginaceae sensu Bauer et al. (1997) has yet to be carried out (Begerow et al., 2006).

Species in Australia
 
Cintractia amazonica
Cintractia axicola
Cintractia bulbostylidis
Cintractia limitata
Cintractia lipocarphae
Cintractia mitchellii

Key based on host taxonomy
 
On Bulbostylis Cintractia bulbostylidis
On Cyperus Cintractia limitata
On Fimbristylis 1
1.  Sori around floral pedicels. Spores 8-18 µm long Cintractia axicola
Sori comprise the spikelets. Spores (10-)11-14.5 µm longCintractia mitchellii
On LipocarphaCintractia lipocarphae
On RhynchosporaCintractia amazonica