The internal transcribed spacers (ITS) of the nuclear ribosomal DNA have been sequenced from 29 collections of Phillipsia, mainly from the New World. The P domingensis complex, collections with a range of colors but otherwise referable to P domingensis s.l. based on spore ornamentation, were studied. Three distinctive species of Phillipsia also were included. The sequences were analysed to infer phylogenetic relationships within Phillipnsia, using parsimony. Morphological features were studied separately, and then evaluated in the context of the ITS phylogeny. Four distinct rDNA lineages, supported by ascospore ornamentation, were identified: the P. crispata the P. domingensis, the P. olivacea and the P. carnicolor lineages. SEM photographs of the ascospores are presented. Phillipsia lutea and another yellow form were nested within the P. dominagensis complex, of those with reddish hymenial colors. Color has been emphasized in taxonomy of Phillipsia, but these results suggest that individuals with strikingly different coloration may be closely related. Levels of ITS sequence divergence in the P. domingensis lineage were low. Based on these data, and morphology as studied thus far; there is no justification for recognizing segregate species within the P. domingensis complex. The Old World collections of the P. domingensis complex were nested within the New World collections, which implies that the P. domingensis lineage is geographically widespread. Phillipsia rugospora is plated in synonymy with P. olivacea and a detailed description of this taxon is given. A lectotype is designated for P. olivacea.
The order Pezizales has been divided into two suborders. One suborder, the Sarcoscyphineae, was originally described to include members whose asci were characterized by an unusual apical structure, the suboperculum. Disagreements as to how this structure should be defined, and indeed, whether or not it exists at all, have rendered the status of the suborder controversial. The two families within this suborder are the Sarcoscyphaceae and the Sarcosomataceae. Recent ultrastructural work demonstrates that there is an apical thickening which is restricted to the Sarcoscyphaceae. In order to test the monophyly of the suborders of the Pezizales and examine the relationships within the Sarcoscyphineae, phylogenetic analyses were carried out using DNA sequence data from the 18S rRNA gene. The strict consensus tree based upon these data shows both the Sarcoscyphineae and the Pezizineae as paraphyletic. These data suggest that the subordinal taxa currently recognized within the Pezizales should be abandoned and the taxonomy revised to reflect phylogenetic relationships. Strongly supported clades (i.e., greater than 95% bootstrap value, 1500 replicates) include: the Pezizaceae, the Morchellaceae, the Sarcoscyphaceae, the Helvellaceae, and a clade that includes the Sarcosomataceae (which is paraphyletic), and the Otidiaceae (represented only by 2 taxa). The genus Pindara, formerly placed in the Sarcoscyphaceae, is nested within the Helvellaceae, and Wynnea, assigned to the Sarcosomataceae by some authors, is positioned in the Sarcoscyphaceae.
The literature on teleomorph-anamorph connections in the Orbiliaceae and the position of the family in the Leotiales is reviewed. 18S data show that the Orbiliaceae occupies an isolated position in relationship to the other members of the Leotiales which have so far been studied. The following form genera have been studied in cultures derived from ascospores of Orbiliaceae: Anguillospora, Arthrobotrys, Dactylella, Dicranidion, Helicoon, Monacrosporium, Trinacrium and conidial types that are referred to as being Idriella-like. Characteristics of the anamorphs are discussed and illustrated. Analyses of the ITS region of several of the isolates indicate that there are several well-supported clades within the Orbiliaceae. These clades can be recognized based on the anamorphs produced. They are: an Arthrobotrys-Monacrosporium clade, a Dicranidion clade, and a Helicoon clade. Outside of these clades is a well-supported clade which contains two Arthrobotrys isolates which were derived from conidia produced on natural substrates. The taxonomic and phylogenetic implications of this information are discussed. The Orbiliaceae occur in nature on substrates that are either continually wet or on substrates that periodically dry out. Field observations indicate that those taxa which occur on wet substrates produce perennial mycelia. Some discussion is provided on the way in which scientific information is viewed and can be used.
Cultures derived from ascospores of two collections both referable to Orbilia auricolor produced anamorphs which were assigned to Arthrobotrys cladodes var. macroides and A. oligospora var. oligospora. These morphologically distinct isolates formed nematode-capturing hyphal networks when nematodes were present. Descriptions of the Arthrobotrys isolates are given. At least one other nematophagous hyphomycete is connected with a teleomorph that can be referred to O. auricolor suggesting that O. auricolor is not a single entity but a species complex.
Cultures derived from a collection of Orbilia fimicola produced an Arthrobotrys anamorph. This anamorph was identified as A. superba. A discomycete agreeing closely with O. fimicola was previously reported to be associated with a culture of A. superba but no definitive connection was made. In the present study, traps were formed in the Arthrobotrys cultures when nematodes were added. The hypothesis is put forth that other Orbilia species might be predators of nematodes or invertebrates based on their ascospore and conidial form.
Byssonectria, previously placed in the Hypocreales, is treated as a member of the Pezizales; Pseudocollema and Inermisia are considered synonyms. Four species are recognized from North America: B. terrestris, a new combination which provides the oldest traceable name for the common North American and European species; B. cartilagineum, also a new combination, is based on the type species of Pseudocollema; B. fusispora; and B. seaveri, a new species for a large-spored North American collection. The ascomata of Byssonectria cartilagineum and B. terrestris are initially cleistohymenial. They open during the mesohymenial phase. The ascogonium is a multicellular filament, one cell of which produces ascogenous hyphae. This filament becomes surrounded by vegetative hyphae which build up the body of the ascoma. Young cleistohymenial ascomata could be mistaken for perithecia; such a mistake seems to account for original placement of the type species of Byssonectria in the Hypocreales.
The name Peziza nivalis is used for a species of Peziza collected on soil at the margins of melting snow in the Sierra Nevada of California. The species is described and extensive comments are made on the nomenclature of this and related species. A new species, Peziza heimii, is proposed to accommodate a species similar to P. nivalis but with larger ascospores.