But then yesterday, while weeding, it caught my eye. Each of the tips of the leave serrations sparkled with a drop of dew, and yet the nearby leaves of other plants were dry. Suddenly this ordinary plant stood out from all the others.
This plant turns out to be Lady’s Mantle (Alchemilla mollis). It is a perennial plant for shade gardens, which is not generally well known, but is a favorite among some gardeners as well as photographers.
Another popular feature of Lady’s Mantle is the way the leaves unfurl in a way similar to a paper fan.
In my first posting of this article, I reported that the water droplets were dew from the previous evening. As it turns out, these beads of moisture are not collected by the leaves, they are excreted by them. This process is known as guttation. Guttation occurs when the soil is moist, the humidity is high and the air is relatively cool. At night the leaf pores (stomata) are closed, but the roots are still drawing in water. This builds up water pressure. When the pressure gets high enough, water drops are released through special cells on the leaf margins called hydathodes.
Although Lady’s Mantle is a master of guttation, it is not the only plant that has this ability. Chrysanthemums and strawberry plants as well as many other perennials and annuals also employ this process to a lesser degree.
From my observation of this plant, I have learned that what you think you are seeing, may be something else entirely. In this case it turned out to be the exact opposite of what I believed it to be. It also made me realize how nice it is to have an arborist in the family. My Uncle put me on the right track on this post (see the comments below under the name Bruce Hagen), and has lent his knowledge to, and expanded the scope of my posts through his comments. Thanks Uncle Bruce for your contributions!