Have you ever wondered what those small sticky drops on the back of your Philodendron’s leaves are? If so, you’re not the only one!

The phenomenon we’re talking about is often mistaken for bug damage or even a disease in the plant, and although it is bug related in nature, it is however not a sign of damage to the plant, but something called extrafloral nectaries.
Extrafloral nectaries are, as the name suggests, nectar; a sugar-rich liquid which is produced by the plant in order to develop a symbiotic relationship with ants in the wild. 

Philodendrons begin in the still young, not completely expanded, organs, and extend to the leaves of the second or third node from the base and it stop as the leaf hardens off, and then often fade away. 
Extrafloral nectaries appear in a wide range of size among the studied species, but rarely have a diameter above 1mm.

Extrafloral nectaries are most often found on the leaves and petioles of the plant, and although they can be quite small and discrete, you can spot them by their different coloured border, usually yellow, black, purple or green, or wine-colored, which add an extra pop of color to the plant!

In some cases you can observe an excessive production of nectar which can leave the surface of the plant covered with it. Nectar droplets can leave a yellow spot on the leaf, which does not look attractive, nevertheless it’s harmless and should not be confused with pests. Extrafloral nectaries are not harmful to the plant and represent a natural part of the plants life.

Fun fact: the drops actually have a sweet taste, and are edible on some plants. But please check if yours is one of them before trying!
Extrafloral nectaries are only found on Philodendron, Alocasia, and Culcasia among Aracae family.