Odd Crystals on my Aroids, Nemanthus leaves

[IndoorJungle]

Hello! For the last few weeks, different aroids have had yellowing leaves on the lower portion of their vines which eventually die. The margins of their leaves have these little white crystals, but no sign of anything living causing them harm!

Does someone know what this could be? Thank you!

 

[Chuck]

If I were to guess I'd say it is a phenomenon known as guttation and the excess water evaporates and leaves the crystals behind. Either this or it is from excess water being exuded through the leaves and then evaporating and leaving behind salt crystals from mineral salts in the water. These salts can come from different sources including the water itself and from fertilizers. Neither will harm your plants.