M. Piepenbring et al., Molecular sequence data assess the value of morphological characteristics for a phylogenetic classification of species of Cintractia, MYCOLOGIA, 91(3), 1999, pp. 485-498
The genus Cintractia s. l. (Ustilaginales, basidiomycetes) comprises about
40 species of smut fungi infecting Cyperaceae and Juncaceae. These organism
s form a phenetic continuum with respect to their sets of morphological cha
racter states, which do not allow a clear delimitation of infrageneric grou
ps. According to sequence data of the large subunit ribosomal DNA of 17 spe
cies of Cintractia s. I. and related taxa of other genera of smut fungi, Ci
ntractia s. l. is polyphyletic. Five groups of species shown by sequence da
ta are characterized morphologically as different genera: Cintractia s. s.,
Tolyposporium, and the new genera Gymnocintractia, Leucocintractia, and St
egocintractia. Species of Cintractia s. s. and Tolyposporium form one clade
, which is supported morphologically by similar soral structure. In the phy
logram based on large subunit rDNA sequence data presented here, Cintractia
s. s. seems to be paraphyletic, but the bootstrap values of this topology
are very low and members of Cintractia s. s. and Tolyposporium are morpholo
gically easily distinguishable by the presence of irregularly roughly warty
teliospores in balls in species of Tolyposporium and single, finely warty
teliospores in species of Cintractia s. s. Species of Gymnocintractia and t
hose of Leucocintractia are sister taxa, although the former are similar to
species of Stegocintractia by the absence of a sterile stroma in the sori
and foveolate teliospores, and the latter to those of Cintractia s. s. by t
he presence of a sterile stroma, peridia, and nonfoveolate teliospores. Dis
tinctive morphological characteristics were, however, found, such as the pr
esence of fungal peridia in sori of species of Stegocintractia and their ab
sence in those of species of Gymnocintractia, teliospores with rough warts
forming ridges in species of Leucocintractia and finely warty ones in speci
es of Cintractia s. s. Hosts of species of Cintractia s. s., Gymnocintracti
a, and Leucocintractia belong to the Cyperaceae, those of species of Stegoc
intractia and Tolyposporium to the Juncaceae.