flowers-of-an-hour n 1: annual weedy herb with ephemeral yellow purple-eyed flowers; Old World tropics; naturalized as a weed in North America [syn: {flower-of-an-hour}, {flowers-of-an-hour}, {bladder ketmia}, {black-eyed Susan}, {Hibiscus trionum}]
flowers-of-an-hour \flowers-of-an-hour\ n. An annual weedy herb ({Hibiscus trionum}) with ephemeral yellow purple-eyed flowers, native to the Old World tropics and naturalized as a weed in North America. Syn: flower-of-an-hour, bladder ketmia, black-eyed Susan, {Hibiscus trionum}. [WordNet 1.5]