Mosses are everywhere! But there are no liverworts!
I had intended on this blog post being about mosses and liverworts. Back home in the deep south, it can be so hot and dry that the liverworts are very hard to find there. I always look for them when I am up north. We had a good rain, which really makes these plants grow like crazy. Mosses were in abundance, but I could not find the liverworts this year. I looked in all the places that I had found them before, but it seems they are hiding from me this year.
As I strolled through the woods today, I noticed that the mosses were just beautiful.
Mosses are nonvascular plants called Bryophytes, sometimes referred to as the “in-between” plants. When I am teaching my students about Bryophytes, I refer to them as the “amphibians of the plant kingdom”. This really helps my students remember the key points about the Bryophytes.
Like the amphibians, the Bryophytes live on land, but are not well adapted to life on land.
First of all, they do not have any vascular tissue. Vascular tissue (xylem and phloem) is the conducting tissue within a plant. Xylem consists of long tubes that carry water from the roots to the top of the plant. The phloem consists of long tubes that distribute glucose and other organic compounds from the leaves throughout the plant. The mosses are nonvascular, meaning that they do not have xylem or phloem.
Another characteristic that makes the mosses poorly adapted for life on land is the presence of motile gametes …… a swimming sperm! When it rains, the mosses will rush to produce reproductive structures because the only way for sperm to reach the egg is by swimming in rainwater.
The true land plants are tracheophytes. They are well suited to life on land because they are vascular plants. They have xylem and phloem to transport food and water long distances. Tracheophytes do not depend on water for reproduction. These plants evolved a much more efficient sperm delivery system. Pollen!
Tomorrow I am going on a hunt for pitcher plants. There is a bog near our cabin where the pitcher plants have thrived in years past. It is extremely dry from lack of rain, so I am keeping my fingers crossed that the pitcher plants have survived. Stay tuned …….