ABSTRACT
We are concerned with physiological adaptations in a relatively small group of closely related fungi in the family Clavicipitaceae. These organisms are broadly distinguished as being symbiotic associates of either insect and fungi ( Cordyceps spp.), or grasses, rushes, and sedges (Balansia, Claviceps, Myriogenospora, Epichloe, Echinodothis, Atkinsonella, and Balansiopsis). The species of the genus Cordyceps will not be considered in this discussion, which will focus instead on symbiotic fungal associations with grasses. These fungi are either entirely systemic and endophytic, or epibiotic symbionts of their hosts. Also included in this discussion are the species of Neotyphodium, the anamorphic states of Epichloe (Glenn et al., 1996). Many are intercellular in their distribution within the host, and this distribution is usually restricted to the ovary-floret, or foliage and above-ground portions of grasses and their allies. Thus, we are dealing with intercellular foliage symbionts which should be contrasted with the examples of intracellular root and woody stem symbionts presented elsewhere in these proceedings. Intercellular fungi apparently have an immense biological consequence on grasses since they are found associated with most of the tribes of the Grami-
neae. Endophytic associations are established at the seedling stage and are remarkably long-lived; for instance, clumps of endophyte-infected tall fescue persists for decades.
