Houseplants are always working hard to adapt to their environments and one way they do this is by creating extrafloral nectaries – these tiny, usually overlooked structures actually play a huge role in a plant’s well-being! Check out below to learn what they are, how they occur, and why they’re a sign of a happy and healthy plant!
What are EFNs?
Extrafloral nectaries are special glands that can be found on many parts of the plant including the leaves, stems, and petioles.
Unlike nectaries in flowers that attract pollinators, EFNs exude a sugary liquid (nectar) meant for a different group of visitors – ants and other beneficial pests.
EFNs are commonly mistaken for signs of fungal damage and while the shape of these spots are similar, the colorings are different. Fungal spots often have a dark center and a yellow or orange-toned “halo” surrounding the spot.
How do they happen?
The formation of EFNs is a fascinating process rooted way back in the plant’s evolution.
The nectaries typically develop in response to environmental cues like insect attacks or the search for resources. When the plant senses a threat, such as herbivorous insects or potential invaders, it goes into protective mode and starts producing EFNs in strategic locations like leaves and stems. The nectaries are there to attract helpful insects like ladybugs who use their strength to defend the plant.
Most commonly, you’ll spot EFNs on Philodendron varieties like upright ‘Ring of Fires’ and trailing ‘Micans’, among others.
Are they harmful?
The presence of EFNs is a great sign that your plant is thriving! It means that your green friend is actively monitoring its surroundings and responding to any threats it may sense.
EFNs and the nectar they produce are harmless to the plant and serve as a mutually beneficial relationship between the plant and any helpful insects it may attract. When insects (like ladybugs) are lured in by the sweet nectar, they might just decide to stick around and act as bodyguards for your beloved foliage. It’s a natural and sustainable form of pest control!
Once on the leaf, the spots that EFNs leave behind won’t go away but you can admire your plant with love even despite these blemishes.
Extrafloral nectaries are a remarkable example of how plants adapt and interact with their environment. Next time you see these small spots on your houseplant, remember there's a lot going on that you can't see – these spots are part of your plant's natural defenses, keeping your greenery happy and healthy.
