An Introduction to the Lovely Mosses and Other Bryophytes of the UW Lakeshore Nature Preserve 27 August 2023

Field trip leader Brandon Corder displays a liverwort. Photo by Will Vuyk.

UW Department of Botany doctoral candidate Brandon Corder ([email protected]) attracted 26 participants for this fascinating walk. As Brandon’s research is now focused on the relationship of orchids with fungi, Masters student Nkosi Evans, who is actively studying mosses, assisted him.  After introductions by Hosts Will Vuyk and Doris Dubielzig at the Picnic Point entrance kiosk, we walked to a shady, wooded spot where Brandon pointed out moss growing on the bark base of a white oak tree. After looking carefully at mosses growing on the logs lying on the ground around us, Brandon explained that mosses are primitive plants that have neither flowers nor seeds.
Moss ecology causes different species to occur in layers on logs and at different heights on tree trunks.

They are difficult to identify, because

• Key features, like the teeth on spore capsules, are microscopic
• They don’t often have common names
• They’re small!

​Consequently, genetic analysis is now used to identify moss species.
Brandon pointed out the glossy green seductive entodon (Entodon seductrix). The less shiny, filmier, Leskea grows on higher, drier parts of tree trunks.

Glossy, green seductive entodon (Entodon seductrix). Photo by Mary Prior.

Leskea is a less shiny and more filmy moss. Photo by Mary Prior.

On the ground below a maple tree in Caretaker’s Woods, Brandon showed us a large patch of Anomodon that exhibited the moss lifecycle, which has two distinct stages.  The green, leafy tissue produces the gametes – the eggs and sperm.  After fertilization (the union of the egg and sperm), an elongated red capsule forms that contains the spores. After the spores scatter, they create more of the green, leafy tissue.  In addition to sexual reproduction, Anomodon has asexual, vegetative reproduction.  

Amomodon green leafy tissue and red spore capsules. Photo by Doris Dubielzig.

On Frautschi Point, Brandon introduced us to fern anatomy and three kinds of ferns.  Because they have vascular systems for transferring water and nutrients, ferns are generally larger than mosses.  Ferns have two essential parts: 1) the leaf = “frond” and 2) the stem = “rhizome,” which is usually underground.
The Wood fern has a large leaf (“frond”) which is subdivided into leaflets (pinnae) and subunits (pinnules).  On the underside of the frond are many spots or “sori” which contain the spores.
 
Brandon showed us a large patch of Ostrich fern, which has the sori all grouped together on a special fertile frond.  He also described the Interrupted fern, that has some sterile pinnae and some fertile pinnae.

Underside of a Wood fern frond, showing its tidy rows of sori (spore patches). Photo by Doris Dubielzig.

Fertile (spore bearing) frond of Ostrich fern. Photo by Doris Dubielzig.

Finally, Brandon showed us a sample of liverwort.  This relative of mosses usually has a flat plant body (“thallus”).  Liverworts have high moisture requirements, which prevented us from seeing them in their habitat.  I have seen them from a canoe on the rock wall rising above Lake Mendota’s surface, west of Raymer’s Cove,.
 
Thank you, Brandon Corder, for your thoughtful preparations and clear explanations. 
 
Report by Doris Dubielzig, photos from Mary Prior, Doris Dubielzig, and Will Vuyk