Figure 3: Caption: Symptomatic tomato tissue was placed in a dish and covered with water. Within 48 hours, Phytophthora sporangia began to grow profusely from the infected, symptomatic tissue. A) green tissue on the infected fruit, B) brown tissue on the infected fruit, both with significant amounts of sporangia. C) A sporangium floating in the water. It has a distinct pear-to-lemon shape. D) Oospores, the overwintering structure produced by Phytophthora, have a thick double wall and can develop in the infected plant tissue (bottom left structure) (Photo by John Bonkowski).