I recently planted up this garden and this bed near the entrance with some bird and butterfly attracting plants and see how the Danainae (or milkweed) butterflies such as the Plain, Black Veined and Blue Glassy Tigers all flocked to this mysterious plant known as the Heliotropium indicum.
The plant is not aesthetically pretty, and is in fact unhealthy or diseased looking. But it contains compounds known as pyrrolizidine alkaloids, which are used by these butterflies as defense mechanisms against insectivores which feed on them. These alkaloids are also known to cause hepatotoxicity or liver damage.
On a separate note, the last photo is of an uncommon Heliconia episcopalis which I planted nearby.