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Two new species of hyphomycetes, Xenocylindrocladium guianenseand X. subverticillatum, are described from plant debris collected in French Guiana and Singapore, respectively. The genus Xenocylindrocladiumhas thus far been known from one species, X. serpens, which was described from plant debris collected in Ecuador. The two new taxa are compared with and distinguished from X. serpensbased on morphology, cultural characteristics and phylogenetic analysis of DNA sequence data of the 5.8 S rDNA with flanking ITS1 and ITS2 regions and the 5' end of the β-tubulin gene. These species are also compared with other closely related hypocrealean taxa. Present collection data suggest that species of Xenocylindrocladiumcould be restricted to the tropics.

During an examination of Coniothyriumcollections occurring on Proteaceae one species, C. leucospermi, was repeatedly encountered. However, it was not always possible to identify this species from host material alone, whereas cultural characteristics were found to be instrumental in its identification. Conidium wall ornamentation, which has earlier been accepted as crucial in species delimitation is shown to be variable on host material, making cultural comparisons essential. Using standard culture and incubation conditions, C. leucospermiisdemonstrated to have a wide host range in the Proteaceae. In addition, microcyclic conidiation involving yeast-like budding from germinating conidia and hyphae in culture is newly reported for this species.

Leaf discs provided better recovery of Cylindrocladium candelabrumfrom soil than stem or twig segments. Leaf discs of eucalypt (Eucalyptus grandis), azalea (Rhododendronsp.), and geranium (Pelargoniumsp,) were the best of seven plant baits evaluated. Twig segments of azalea and eucalypt also provided a high percentage of the pathogen recovery, whereas stem segments of pine seedlings (Pinus elliottil3proved unsatisfactory. Although slightly less effective, twig segments were easier to handle than leaf discs which were quickly decomposed in soil. Colonization of eucalypt twig segments by Cylindrocladiumspp. varied with inoculum level, soil moisture content, and incubation period. The highest percentage of recovery of C. candelabrum(approx. 95%) was calculated at a field capacity moisture level of 155.9% after 75h of incubation.

A Calonectriasp. forming a Cylindrocladiumanamorph was found to be commonly associated with leaf spot and cutting rot of Eucalyptusin Brazil, Colombia, Ecuador and Argentina. Based on morphology, isolates of this species resembled Cal. hederae, Cal. reteaudiiand Cy. leucothoes, taxa that are commonly referred to as the Cal. reteaudii-complex.Using DNA sequence data of the ITS1, 5.8S and ITS2 of the rRNA gene, as well as the β-tubulin gene, this species was shown to represent a previously described, but rather poorly known species, Cal. spathulata, for which an emended description is provided. Furthermore, the recently described Cy, perseaewas also shown to be synonymous with Cy. leucothoes, aspecies shown to be distinct from Cy. spathulatum.Based on vesicle and conidium morphology, as well as perithecial colour and ascospore morphology, it appears that Cal. hederaeand Cal. reteaudiishould also be retained as separate species. Additional collections and cultures would be required, however, to suitably characterise the latter two species in future studies.

Cylindrocladium angustaturnis described as a new species from Tillandsiaintroduced with plant material into the U.S.A. from Central America. Koch's postulates are established to prove its pathogenicity to this host. The species is compared with and distinguished from C. heptaseptatumand C. rumohraebased on morphology, cultural characteristics and phylogenetic analysis of sequence data of the beta-tubulin gene.

Fungal endophytes were isolated from leaves, roots and stems of four wheat cultivars and a breeding line at three different sampling dates during the 1993 growing season. Of the 55 different fungal taxa encountered, 19 were present at relative importance values of more than 5%. No cultivar-related differences in the assembleges of endophytes were observed. Phoma glomeratawas not restricted to only one tissue type, whereas Aiternaria alternata, basidiomycete sp. 1, Pleospora herbarumand Epicoccum nigrumoccurred primarily in the leaves, and Fusarium avenaceumwas extremely frequent in roots. In general, colonization by endophytes increased with the age of the plants. Most endophytes were isolated from wheat leaves. Successional colonization of a given tissue type was quantitative rather than qualitative, with a given fungal taxon increasing or decreasing over the period sampled, rather than replacing the fungi initially encountered.