1. (noun) annual weedy herb with ephemeral yellow purple-eyed flowers; Old World tropics; naturalized as a weed in North America

• black-eyed susan
• bladder ketmia
• flower-of-an-hour
• flowers-of-an-hour

1. (noun) annual weedy herb with ephemeral yellow purple-eyed flowers; Old World tropics; naturalized as a weed in North America

• hibiscus