I decided to poke around the bushes outside of the university buildings to see if I could find any bryophytes. What I found were some super tiny hornworts with sporophytes. The cluster here is about the size of my fingernail. There are three main groups of plants that are typically called bryophytes: mosses, liverworts and hornworts.
Hornworts have a flat thallus that grows pressed close to the ground. They do not have stems and leaves as mosses do. Many of the features that set hornworts apart from other bryophytes relate to the sporophytes. They have long, skinny sporophytes that produce spores inside for the entire length. They do not have a swollen capsule as in mosses and liverworts. Pictured here are some very young sporophytes peeking out from the wavy edged hornwort.
The spores are released from these structures by a very interesting mechanism. The oldest and most mature spores are located at the tip of the sporophytes. When they are ready to be released there are 1 to 2 lines that open from the top downward like zippers releasing the spores. The sporophyte continues to grow from the bottom making more and more spores that are released as the opening moves toward the bottom.
This phenomenon is where the common name hornworts comes from. After the spores have been released the sporophyte tip which has been divided in half by the lines of dehiscence (aka. zippers) dries and curls. They look like two horns, thus the name Hornwort. These photos do not show this neat phenomenon since the sporophytes are really young. Hornworts occur around the world and we have them in Connecticut too.
Keep your eyes peeled for these curly tipped sporophytes which tell you that you have found a hornwort. It is a good feature to know about when searching for them.