Plants from a unique ecological environmental niche, and growing in special habitats, especially those with an unusual biology and possessing novel strategies for survival should seriously be considered for study. Strobel et al. (1999a) showed that an aquatic plant, Rhyncholacis penicillata, which lives in harsh aquatic environment which may be constantly wounded by passing rocks and other debris, resists infection by common oomyceteous fungi (water molds that are phytopathogenic) that cause disease. The possibility that endophytes associated with this aquatic plant may produce antifungal agents that protect the plant from attack by pathogenic fungi is feasible. A novel antioomycetous compound, oocydin A (Fig 4) was discovered from the endophytic strain Serratia marcescens from this plant.