January is the month my couple of Phalaenopsis orchids send up a spike with flower buds on them. The buds usually open during the last weeks of the month. I discovered one orchid stem and buds looked a bit shiny. Upon closer inspections, I saw a droplet of an amber-colored thick liquid. The stuff was sticky! It appeared to be maple syrup. I gently washed it off under tepid water. The next day it was back. I checked for insect feeding that might have caused damage and weeping, or insect excrement. None. After watching for several days, more sticky stuff appeared, almost coating the buds. After a bit of internet hunting on University researched sites on orchids, I found nothing indicating this as a problem. An informal search of ‘Sticky Stuff on my Orchid’ returned several answers. It is normal for some varieties. They called it ‘Happy Sap’. If the orchid is happy with its environment, temperature and humidity, it will produce this high sugar sap emitted from the stem surrounding the buds to entice pollinating insects to visit the plant. Once the buds open into the flower containing the pollen, the insects will be present to land on the flower and ensure pollination. The orchid has developed this appetizer to the main meal of the flower, just enough sweet sap to entice the insects to hang around for the real show and nectar.
Another plant that emit sweet, sticky gel is the sundew, botanically named Drosera . These plants attract the insects to the sweet sap, which then get stuck in the sap on the leaf. The plant then eats the insect, absorbing the insects nutrients as it decomposes. These plants are carnivorous. Still another carnivorous plant is the Pitcher Plant which lures insects down its throat where it becomes trapped in a pool of gooey sap, never to make its way back out. I took a cold walk to the UConn Ecology and Evolutionary Biology’s greenhouse to snap a few pictures of plants with happy sap and enticing sweet liquid emitters. EEB greenhouses are open to the public and a great way to beat the winter cold. http://florawww.eeb.uconn.edu/visiting.html