I woke up on a mission to find some mosses and look at them on the road with a microscope. I prepped my gear in the morning into a paper Trader Joe's bag and hopped in the car. My Dad was having a good day so he came along for the ride. We decided to go up to Mt. Baldy.
The weather was concerningly beautiful for late January, sunny and pushing 80F. There was no snow at the parking lot for Mt Baldy ski resort (6300’) and I was comfortable in a short sleeve shirt and long pants. Yes, the weather in Southern California is as variable as it gets but every warm day in winter leaves me anxious.
A few miles down from the ski resort was a pull out next to a creek. This seemed like a great place to find some moss so we stopped. There were a couple families by the water enjoying the beauty of the San Gabriels. We smiled and waved at each-other and I went up the way to find some moss.
Like most streams with year-round water in the San Gabriels, this one was lined with massive Alnus rhombifolia trees and they happened to be blooming. I was looking for moss but what a great opportunity to photograph one of LA County’s best trees. Alder's are monoecious, meaning both male and female flowers are present on the same plant. The flowers on Alders are long, dangly clusters called catkins. The longest catkins at the end of the stem are the male flowers, while the adjacent, more cone-looking structures are the female ones. Our native oaks and walnuts also produce Catkins as flowers, which is not too surprising because all three trees are in the Fagales order.
White Alder’s are winter deciduous and the ground was covered in a layer of last year's foliage. The trees had only flowers growing and each had thousands. I thought it would be better to flower while still having leaves to generate sugar, but what I think about plants is usually wrong. Flowering after dropping the leaves was working just fine for the Alders and I got yet another mystery to think about.
I did find some moss in deeper shade by the Alders. At the scale of most plants, mosses look the same to me. Sure a few will have larger leaves and maybe the sporophytes will differ in color and shape but there is not much difference when viewed from 3-4 feet away. Zooming in with a macro lens on my camera revealed a few more differences but not many. One of the mosses I saw had little white hairs growing from the leaf tips and another looked a bit “stringy”. I needed to accomplish my goal for the day and whip out the microscope in the field to really see the little plants.
To use the microscope, I first had to make the slides. This involves dissecting a small piece of moss and placing individual leaves on the glass. I did my best getting individual leaves but working with my hands at the scale of moss is hard. My method for ID’ing moss so far is to consult this Moss Morphology article that has great drawings of moss anatomy while working with the Key to California Mosses from Jepson. This ID method is not working well and I mostly just have fun looking through the microscope. Moss leaves are usually only one cell thick and lines of grid pattern on the leaves are outlines of individual cells. Under the microscope and at the scale of moss, the differences were clear. One had serrated leaves, one had an awn with slight barbs. My mind was blown. I still have no clue how to really ID a moss but the whole process of seeing plants at the cellular level was very cool.
This first moss I am going to call Syntrichia princeps, aka Brown Screw Moss of the Pottiaceae family. This is the one with the long transparent awns extending from the leaf tips. To really get to Syntrichia in the key, I would have had to cut a small cross section of the already tiny leaves. I'm mainly going off iNat photos and vibes for ID purposes at the moment. The vibes feel good for Brown Screw Moss but I would like to attempt the cross section someday soon.
The second I am calling Funaria hygrometrica, aka Bonfire Moss also of the Pottiaceae family. Is this correct? Photos and vibes lean in that direction but Jepson requires close examination of the cell shape in addition to measurement. My ruler is a bit large to measure cell width but I will look into a cheap way to measure moss cells. It seems pretty useful in the Jepson key.
The third moss had the smallest leaves and I’m going with Amblystegium serpens. I am learning some moss terminology as I practice with the key. A “Costa” is the line of cells in the middle of the leaf that looks like a vein. The first two plants have well defined costa while this one seems to lack one. Even better, the margins on the other two leaves were smooth while this plant has clearly serrated edges. Serration at the cellular level was extremely cool to see.
Next week is calling for lots of rain and I plan on looking for more moss. Looking through the scope today gave a similar thrill to my first days trying to ID plants a few years ago and I can’t wait.