Years ago I thought Hibiscus were very gaudy. My bog bed has several varieties planted in it. Lets face it, a bog bed has a limited selection of plants that will grow in it so I had to plant them. Turns out hardy Hibiscus are incredibly showy and because the flowers are huge, very visible from afar.
Rudbeckia Herbstonne is another moisture loving plant. The foliage is about 18 inches tall but the flowers tower over the plant to 6 feet high. I have quite a few Rudbeckia varieties in the gardens because they all have interesting attributes.
In my dryer gardens I have Verbena bonariensis reseeding like crazy and Tansy. Tansy is an herb that is used for dying. In my case dying yarn. I will collect the flowers this week. They can be used fresh or dried and make a pretty gold color on wool when alum is used as a mordant.