Sorosphaera veronicae Schröeter has been re-discovered in Britain, forming galls on Veronica chamaedrys L. in Middlesex and Northamptonshire. A new host for this fungus, Veronica catenata Pennell, has been found on the banks of the river Thames in Surrey.

The occurrence of the American Horse Chestnut mildew, Uncinula flexuosa, is reported from Europe, including Great Britain, for the first time (New British Record 210). A key is provided for the identification of powdery mildews on horse chestnuts in Europe.

Some fungi are found only in specific geographical regions. The human pathogen Paracoccidioides brasiliensis has only rarely been isolated in nature and incidences of infections are restricted to Central and Southern America. Most commonly infected individuals are not urban dwellers, but rather farmers and people living in mountainous areas. In addition, it is almost invariably males who are infected. The gender bias has been reported as between 10 - 20:1 males over females! A possible explanation for this astonishing and unique phenomenon is given below. P. brasiliensis is the causative agent of paracoccidioidomycosis, a human systemic mycosis for which the portal of entry of the fungus is via inhalation of air-borne propagules into the respiratory tract. After entering the host, the fungus converts spontaneously to its yeast form, a fundamental step for the successful establishment of the infection.

The genus Fusarium is surely known by everyone who looks at moulds associated with plants and soil, especially with its characteristic hyaline, multiseptate, slightly curved macroconidia. Nevertheless, it still seems a daunting task identifying isolates to species. The complexity of the genus is reflected in the number of ascomycete genera such as Nectria, Calonectria and Gibberella, which have Fusarium as the anamorph state. On the other hand many species of Fusarium have no known teleomorph. Colin Booth, President of the BMS in 1977, produced an invaluable monograph on the genus (Booth, 1971) and later, reviews by Nelson et al. (1983) and Gerlach & Nirenberg (1982) also help to make the genus more accessible.

When a major wild bird food producer advised, in their catalogue for the year 2000, that they could not offer peanuts because of the high levels of aflatoxin, the phenomenon of mycotoxins had really come into the public domain. In 2001 the same company was able to advise that 'Although present in some peanut crops this season, aflatoxin is not currently creating any major peanut supply problems'. Mycotoxins, and specifically peanuts and the health of wild birds, were reviewed in earlier volumes of this journal (Isaac 1994 a, b) but the passage of time has not led to any reduction in the problems associated with the presence of mycotoxins in foods and animal feeds. Indeed, the improvement in analytical methods, and the implications of legislation in many countries have served to increase awareness of mycotoxins.

For almost eighty years, I have had an intermittent interest in Ganoderma adspersum and Fomes fomentarius, both of which form large woody basidiomes on the trunks of beech trees. The first encounter with Ganoderma was in Clandeboye Domain near Bangor in Northern Ireland when, after a titanic struggle, a huge specimen was detached from a beech tree and borne in triumph to the Botany Department near the start of my undergraduate life in 1922 at Queen's University, Belfast. A couple of years later I read the first two volumes of Buller's ‘Researches on Fungi’ and was excited by his perceptive analysis of Ganoderma in relation to spore liberation (Buller, 1922).

Twenty years ago a clinician could have been excused for being largely ignorant about fungi as disease causing agents. How things have changed! In the league table of serious infections in which microbes enter the bloodstream (septicaemia) and then challenge the functioning of the vital organs, the fungus Candida albicans (Robin) Berkhout has risen through the ranks of obscurity to rival some of the most common bacterial septicaemias (Calderone, 2002). It may not be appreciated that there are many more Candida infections and Candida-related deaths than there are, for example, cases of bacterial meningitis. In fact, there is a small group of Candida species that cause disease of which C. albicans is the most common and important. It is therefore right to know this yeast as fungal public enemy number one. If a doctor diagnoses a bacterial blood infection, in most cases a number of antibiotics can be used to treat the condition.

Soil samples collected from glacier banks of Gulmarg, Khilanmarg, Sonamarg and Tangmarg of Kashmir valley, were examined for the prevalence of keratinophilic fungi and related dermatophytes. From the 72 positive samples (67.3 %), a total of seven genera with eleven species were isolated viz. Chrysosporium keratinophilum (3.7 %), Chrysosporium tropicum (5.6 %), Chrysosporium state of Ctenomyces serratus (11.2 %), Geomyces pannorum (2.8 %), Malbranchea sp. (0.9 %), Microsporum gypseum complex (20.6 %), Microsporum nanum (1.9 %), Microsporum vanbreuseghemii (0.9 %), Trichophyton ajelloi (15 %), Trichophyton terrestre (2.8 %) and Uncinocarpus reesii (1.9 %).

Name of fungus

Teleomorph: Rhytisma acerinum (Pers.) Fr. (order Rhytismatales, family Rhytismataceae)

Anamorph: Melasmia acerina Lév.

Introduction: Features of interest

Tar-spot disease on leaves of sycamore (Acer pseudoplatanus L.) is one of the most easily recognised foliar plant diseases caused by a fungus (Figs 1 and 4). First described by Elias Fries in 1823, knowledge of it had become well-established by the latter half of the 19th century (e.g. Berkeley, 1860; Massee, 1915). The causal fungus, Rhytisma acerinum, occurs in Europe and North America on A. pseudoplatanus throughout its distribution range and also on other species of Acer (Sutton, 1980; Farr et al., 1989), but it is less frequent in urban and industrial areas.

The black tar-spots visible in late summer and autumn are stromata containing many apothecial rudiments, but these only mature to form asci during the winter on fallen leaves (Jones, 1925; Duravetz & Morgan-Jones, 1971). Maturing apothecial stromata develop linear or convoluted ridge-like swellings which raise the thick black layer (clypeus) on the upper surface of the stroma (Fig 1). Eventually, the surface breaks along the ridges (Fig 2), exposing a greyish hymenium (Fig 3) which contains club-shaped asci and filamentous paraphyses with curved or recoiled tips (Figs 8 and 9). The ascospores are unicellular and needle-shaped, with an apical mucilage pad (Fig 10). In Britain and Europe, ascospore discharge from overwintered stromata takes place in March and April, just as the new sycamore leaves unfold.

Opportunistic fungal infections have emerged in the past ten to twenty years as some of the most significant and potentially lethal infectious diseases to confront contemporary medicine. Fungi such as Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans have emerged from obscurity to threaten many patient groups. Although the latter of these, the yeast C. neoformans, was identified as a potential pathogen as early as 1894, it was not until the 1950s that a systematic appreciation of its potential as an opportunistic pathogen began. During this decade the association between the heightened risk of C. neoformans infection (cryptococcosis) and various cancers of the blood became obvious. Fortunately, just as the risk posed by this yeast to human health was being clearly defined (in the late 1950s), the first effective therapy to treat cryptococcosis appeared - the drug amphotericin B. This was particularly timely since it had been recognised that C. neoformans infection often led to a rapidly fatal form of meningitis if untreated.

Throughout the 1960s the infection remained relatively rare, being largely confined to the patient group described above. However, by the late 1970s the incidence of C. neoformans infection began to rise rapidly. Cases were now being seen in patients undergoing organ transplantation, in those with autoimmune diseases and in others who were receiving immunosuppressive drugs to treat various cancers. Cryptococcosis had suddenly become 'the awakening giant' amongst fungal infections (Kaufman & Blumer,1977); but quite how much of a ‘giant’ would only become clear in the next two decades with the development of the human immunodeficiency virus (HIV) epidemic.

Three species of Lentinus from Cameroon, L. sajor-caju (Fr.) Fr., L. squarrosulus Mont. and L. velutinus Fr. Were investigated in laboratory culture. L. velutinus produced xylarioid outgrowths in both monosperm and polysperm cultures, but these structures were observed only to a lesser extent in polysperm cultures of L. squarrosulus, and those of L. sajor-caju, as well as their respective monosperm cultures, remained sterile. Extracellular oxidase tests revealed all three species to be white-rot fungi.

Mycophagy of Biscogniauxia stromata by rats and beetles on New Zealand's offshore islands is illustrated and discussed.

In October 2001, Sir Paul Nurse and Dr Tim Hunt of the Imperial Cancer Research Fund became the first Britons since 1988 to win the Nobel prize for Physiology or Medicine. The prize was shared with Dr Leland Hartwell, director of the Fred Hutchinson Cancer Research Center in Seattle, and acknowledged the extraordinary progress made by the three scientists in identifying the molecules that orchestrate the growth and division of cells. Two British scientists winning a Nobel prize is reason enough to celebrate, but what made this achievement particularly pleasing was that many of the key experiments were carried out in fungi.

In the early 1970's, Hartwell recognised the potential for studying the cell cycle with genetic methods, using as his model the baker's yeast, Saccharomyces cerevisiae (Hartwell, Culotti & Reid, 1970). He isolated yeast cells in which genes controlling the cell cycle were mutated and thereby identified over 100 "CDC" (cell division cycle) genes. One of these (CDC28) was shown to control a key step in the progression from G1 to S-phase, a point known as 'Start' (Fig 1). Inspired by Hartwell's work, Paul Nurse took a similar approach using another fungal model, the fission yeast Schizosaccharomyces pombe (Nurse, Thuriaux & Nasmyth, 1976). In the mid-1970's, he showed that a gene dubbed cdc2 had a key function in controlling the transition from G2 to M-phase. DNA sequencing of the gene revealed that cdc2 was very similar to the CDC28 gene that Hartwell had shown to control the transition through Start. In other words, a single gene regulates progression through two key points in the cell cycle in organisms that separated from each other during evolution more than one billion years ago.

Since most mycologists work on ascomycetes or basidiomycetes it is easy to forget chytridiomycetes when thinking about fungi, let alone anaerobic chytridiomycetes. So it was hardly surprising that more than one hundred years ago scientists did not recognise the motile spores in a rumen sample as being fungi. Since it was general knowledge that the rumen was infested with bacteria and ciliates the flagellated cells seen by Liebetanz and Braune (1913; 1910) were considered to be flagellates (see Fig 1). About 50 years later there are some careful remarks in the literature about this Callimastix species by Vavra and Joyon (1966) but they do not explicitly mention that it might be a fungus. It took until the seventies before Colin Orpin finally dared to suggest that those strange anaerobic flagellates that live in the rumen might actually be fungi (Munn et al., 1981; Orpin, 1975; 1977). That scientific dogmas are enormous barriers is obvious from the fact that even the great rumen microbiologist Robert Hungate did not believe that fungi could be anaerobic. The late Rudolf Prins told me that in the sixties, when he and Hungate discovered 'fluffy' colonies in anoxic tubes, they always threw them away because oxygen must have seeped in!

Careful examinations by Heath (1983; 1988b) and Barr (1980; 1988) morphologically linked the anaerobic chytrids to the fungi. Modern phylogenetic analyses have confirmed these findings and reveal the chytrid fungi to be the earliest fungal branch (Bowman et al., 1992; Doré and Stahl, 1991; Li and Heath, 1992; Van der Auwera and De Wachter, 1996).