When I was a child, my friend and I would hunt around outside for some old cast-off can, like a soup or bean can. We'd gather lantana and add some water, stir it with a stick and pretend it was soup fit to eat. Thank goodness our mothers' generalized warnings about rusty cans and not eating this or that from the wild over-rode our play. We never drank our concoction.
I must admit, however, that I was not as careful about other berries and twigs I would find in the wild. All along the way from school to my house I would search out sea grape trees and would stuff myself with the dark purply ripe ones. Now I won't even eat a wild apple without washing it! I confess to eating unwashed thumbleberries that grew wild in Hawaii, though.
Back to Lantana: Lantana is a hardy plant that has, at times, the smell of sage. Best not to get too close, though, as the Lantana leaves are poisonous. The lantana is appreciated by gardeners for its drought-tolerant qualities and brightly colored flowers. The flowers are not poisonous to birds and are used by some male species to decorate their nest in order to attract a female. Many species of butterflies love the lantana. If you want to attract butterflies to your garden, you might try lantana. In many regions of the world, lantana is considered a noxious weed and is not desirable; however, its woody stems are used by some artisans in India in their wicker crafts. Although the ripe berries of the lantana are supposedly non-toxic, again, if ripe, I recommend not putting any part of the lantana plant in one's mouth. Stay safe!
Answer: The reason some people call this plant "Ham and Eggs" is because of the pink flowers (ham) that surround the yellow flowers (eggs.)