Truffle trouble: what happened to the Tuberales?

What happened to the Tuberales? 1083
the family, e.g. Sphaerosoma and Ruhlandiella (as Muciturbo) (e.g.
Castellano et al. 2004). See Figs 2 and 5A-D.
Pezizaceae Dumort. 1829 (syn. Terfeziaceae E. Fisch. 1897)
The family Terfeziaceae as defined by Zhang (1992a, 1992b)
are included in this family, but was accepted in the latest
Dictionary of the Fungi (Kirk et al. 2001). Recent molecular results
(e.g. Norman & Egger 1999; Hansen et al. 2005) clearly demonstrate
it should be relegated to synonymy of the Pezizaceae (see
review in Hansen & Trappe 2002). Thirteen out of 25 genera in
the Pezizaceae (Eriksson 2006a) are exclusively truffle or trufflelike
taxa, but several truffle species have also been described
in Peziza. Hansen et al. (2001) gave a review of the genera.
The genus Peziza was found to be non-monophyletic and all
other pezizaceous genera nested within it (Hansen et al.
2001, 2005), and a revised generic arrangement is under way
(Hansen & Pfister, in preparation.). Two lineages discovered
comprise most of the Peziza species, the Peziza s. str. and the
P. depressa–Ruhlandiella lineages, the latter including several
truffles (Cazia, Peziza ellipsospora, P. whitei, Ruhlandiella, Terfezia
and Tirmania; Fig 2). The P. depressa–Ruhlandiella lineage was
highly supported in combined analyses of LSU, b-tubulin,
and RPB2 (Hansen et al. 2005). Only one truffle genus, Mattirolomyces,
clusters in Peziza s. str. in MP analyses, but without
support (Fig 2). Three types of hypogeous ascomata exist
within the family (Fig 2). The Amylascus–Pachyphloeus and
the P. depressa–Ruhlandiella lineages produce both ptychothecia
and stereothecia. The cardinal feature of Pezizaceae, the
amyloid reaction of the ascus wall, has been lost in several
of the hypogeous taxa (e.g. Cazia and Terfezia).
Amylascus Trappe 1971
Type: Amylacus herbertianus.
The type species of Amylacus has not been sampled for molecular
phylogenetic study, but the genus is most likely monophyletic
[A. tasmanicus has even been considered a synonym
of A. herbertianus (Beaton & Weste 1982)] and is suggested to
be closely related to Scabropezia and Pachyphloeus. Amylascus
was originally placed in the Terfeziaceae or Geneaceae (Trappe
1971, 1975a), but later, based on the thick-walled, amyloid
asci, was placed in the Pezizaceae (Trappe 1979). Trappe
(1975a) and Beaton & Weste (1982) monographed the genus.
Amylascus includes only the two mentioned species, both
recorded only in Australia.
Cazia Trappe 1989
Type: Cazia flexiascus.
Originally, and at times by some subsequent authors,
placed in the Helvellaceae (Trappe 1989), but Kirk et al. (2001)
place it in the Terfeziaceae. O’Donnell et al. (1997) were the first
to place Cazia in the Pezizaceae. As can be seen from Fig 2, itis
nested within the P. depressa–Ruhlandiella lineage containing
both epigeous and hypogeous taxa. Cazia quercicola Fogel &
States (2002) is only the second recognized species.
Eremiomyces Trappe & Kagan-Zur 2005
Type: Eremiomyces echinulatus (syn. Choiromyces echinulatus).
Ferdman et al. (2005) found this species to cluster within the
Pezizaceae (with Terfezia and Tirmania species) and not with the
type of Choiromyces, which has affinities with the Tuberaceae.
Fig 5 – Fruiting body forms in lineage A (Pezizaceae). (A-B) Sarcosphaera coronaria (A) Closed apothecia, JHP-95.074 (C). (B) Open
apothecia. (C) Hydnobolites cerebriformis, ptychothecia. (D) Terfezia leptoderma, stereothecia. Photos: J.H. Petersen (A),
K. Hansen (B), J. Nitare (C), J. Santos (D).