Guttation

Here is MY Cymbidium orchid with the drops of liquid on the bloom stem.  This is called guttation. I'll copy and paste the Wikipedia definition and a couple of their photos to explain what this phenomena is all about.

I am actually very excited about the orchid because it's the first time I've gotten it to rebloom. This type likes a cooler growing area and a distinct drop in the temp at night. So, I'm actually very pleased and surprised that it's going to bloom for me!

Guttation

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Guttation on Equisetum

Guttation on a strawberry leaf

Guttation is the appearance of drops of xylem sap on the tips or edges of leaves of some vascular plants, such as grasses. Guttation is not to be confused with dew, which condenses from the atmosphere onto the plant surface.Process

At night, transpiration usually does not occur because most plants have their stomata closed. When there is a high soil moisture level, water will enter plant roots, because the water potential of the roots is lower than in the soil solution. The water will accumulate in the plant, creating a slight root pressure. The root pressure forces some water to exude through special leaf tip or edge structures, hydathodes, forming drops. Root pressure provides the impetus for this flow, rather than transpirational pull.

Guttation

Guttation is a secretion of fluid from a plant's leaf that comes onto the surface of the leaf out of specialized pores called hydrathodes.

This process happens when the surrounding humidity in the air is high, the soil moisture is high and the rate of transpiration (evaporation) is low. Plants enclosed in a terrarium will sometimes exhibit this phenomenon.

When the water being secreted contains minerals in the solution, like calcium, it will leave a whitish crust on the surface of the leaf when it dries.