You are on an expedition into a tropical rainforest. You notice a tall plant with large, long, conical purple flowers that produce nectar. When you ask your guide about the plant, she pulls out a large pink fruit from her bag and explains that it is from the plant with the purple flowers. After tasting the fruit, you decide to bring the plant back home and cultivate it. Because you live in a different climate than the rainforest, you decide to grow the plants in a greenhouse. You are surprised when, after a few months, no fruit is growing. What can be inferred from this observation?