Group B: The Daldinia eschscholtzii group (Figs 28-41)

The D. eschscholtzii group almost exclusively comprises species from tropical regions, and some of the species are pantropical in their distribution. Only D. caldariorum has made it to Europe. Other species are apparently endemic to the neotropics or to fareastern Asia. It is being treated here extensively, considering that it constitutes one of the most important groups of tropical Xylariaceae. Molecular phylogenetic data helped to define this group, suggesting that it constitutes a sister group to the other Daldinia species. Furthermore, it has a similar secondary metabolism in culture compared to genera such as Phylacia, Rhopalostroma, Ruwenzoria and Thamnomyces (cf. Stadler et al. 20010a, b) and to D. placentiformis (see molecular phylogenies in Bitzer et al. 2008, Hsieh et al. 2005, and the current study). The stromatal morphology within this group is quite variable, ranging in shape from placentiform, turbinate to stipitate, while truly semiglobose, sessile stromata are only exceptionally encountered. Several species contain large amounts of cytochalasins in their stromata, which co-occur with BNT and other naphthalenes. They mostly reveal purple colours in KOH, or, especially in old stromata lacking the pruina, their ectostroma may even lack KOH-extractable pigments. Their anamorphs are nodulisporium- or virgariella-like (rarely approaching periconiella-like with synnematous conidiophores) and show an exclusively holoblastic conidiogenesis.

The core species, D. eschscholtzii, is certainly among the most frequently reported pyrenomycetes of the tropics. It was first described as Sphaeria eschscholzii Ehrenb. (7) from the Philippines. The original illustration by Ehrenberg (1820, reproduced here as Fig. 28) shows placentiform stromata with conspicuous internal zones (the lighter zones up to ca. 2-3 times wider than the darker ones), tubular perithecia arranged in a dense layer, whose ostioles are at the same level as (or somewhat lower than) the stromatal surface, and conidiophores and conidia whose actual size and shape can hardly be determined. As pointed out by Lloyd (1919) and Dennis (1963), the depicted specimen was probably not mature. Apparently, it had just developed perithecia. Neither asci nor ascospores were described by Ehrenberg (1820). The corresponding specimen is no longer extant, hence this illustration must serve as type. Fries (1823) listed it as "Sphaeria concentrica Bolton: Fr. var. eschscholzii Ehrenb.: Fr.". Owing to the prominent concentric zones of the entostroma, it was later transferred to Daldinia by Saccardo (1882), who emphasised the "oblong" perithecia and the "copper-coloured" stromatal surface as main differences to typical D. concentrica. However, Saccardo also stated that the material on which he based his description was from Brazil, rather than the Philippines. Subsequently, the Swedish mycologist Starback (1901) studied material from the Regnell Expedition to Brazil and for the first time described ascospores in connection with this name. Not much later, the German mycologist Heinrich Rehm (1904) described material from Texas as "D. eschscholzii (Ehrenb.) Rehm", and subsequently reported a specimen from Samoa (Rehm 1907), "to agree with the material from Texas". The same author also erected D. luzonensis Rehm (Rehm 1913) from the Philippines, but subsequently (Rehm 1914a,...