Gloriosa superba is a climbing lily, native to India. Its tubers are poisonous, but are useful for treating certain diseases.
Sanchezia is a native of Brazil. Its tubular yellow flowers in orange bracts are as attractive as its striped leaves.
The French Marigold can be planted with the vegetables to ward off pests.
The Four o'Clock flower blooms in all vacant lots in my suburb. The same plant has three different coloured flowers here.
You can see more flower pictures here .
I am also linking up to Today's Flowers.