Calla Lily ( Zantedeschia ? aethiopica )

We have a Zantedeschia that spends the summer outdoors but our weather is such that it won't survive the winter, so it comes indoors for the winter.

The other day I decided it was time to bring it in.  Not having fully decided where I was going to put it I just stood it down in the kitchen.  Today Clickychick shouted me through saying come and look at this.

What I was called to see is called guttation.  It is a natural process where some plants exude drops of liquid at the end of the leaves.  This mainly occurs at night as the open stomata allow surplus fluid to evaporate during daylight.  So when they close at night the plant exudes excess water through pores (called hydathodes).