Minions

Day 240: Some things defy description, and it's my opinion that the spore capsules of many of the liverworts fall within the criteria for "weird." Asterella gracilis (shown here with the fleshy leaves of a sedum) is a good example. When I first encountered these, I shipped off a sample to a liverwort expert in Oregon for identification, although in the interim, Team Biota applied their own common name to the species: Minions.  If you've seen the movies, the derivation should be obvious. Since then, I've learned more about liverworts and have come to regard them with almost as much curiosity as I reserve for slime molds. They are nonvascular, i.e., they lack the vessels which in vascular plants transport water and nutrients. Consequently, they are generally rather small. However, like certain lichens and those creepy, creeping Protists, they are eminently suited to be the pioneers in ecologies which would be inhospitable for other plant types. Most liverworts grow in damp areas because of their inability to retain moisture in their cells.

The Martians Have Landed

Day 225: What strange lifeform is this? It is a bryophyte, but it is not a moss. It is a liverwort, specifically Asterella gracilis. Liverworts are not as abundant as mosses in the Pacific Northwest, and many of them go unnoticed because the leafy forms resemble some of our mosses very closely. This photo shows the female receptacles of this species. These reproductive structures have four or more lobes, each containing a single sporangium (the black "eyes"). As these ripen and prepare to release spores, the involucres (the white X surrounding the sporangia) will separate and will give the receptacle the appearance of having a lacy white skirt around its edge. The thallus (body), hidden beneath the moss, is a small lichen-like rosette, green on top, dark red underneath. Close examination of the thallus with a hand lens will show oil bodies as tiny dots in the tissue, a feature lacking in lichens and mosses.

Asterella Gracilis, Syn. Mannia Gracilis

Day 243: "Minions." That's what Joe thought they looked like. At first glance, I thought they were an odd seed head, but rejected that idea after ascertaining that the adjacent foliage did not belong to the same plant. With my nose only an inch from the rock, I began a search for clues. If you'd been in the area, you'd have heard my whoop of exultation echo off the canyon walls when I found the answer. "It's a LIVERWORT!" At the moment, I had to be content with that alone.

Upon consulting field guides at home, I determined it belonged to the Asterella genus. I suspected it of being A. gracilis, but I had no way to confirm that simply from photos. Another trip was made to obtain a specimen even though I knew I was in over my head. One of my lichenology contacts referred me to liverwort expert David Wagner of the Northwest Botanical Institute in Eugene OR. After obtaining permission from the Park's Plant Ecologist to refer the specimen out for analysis, I mailed it to David. When I got home from work last night, his reply was in my email: "I have received the capsules and the spores show this is Asterella gracilis. Its reddish coloration on the carpocephala is not typical and the spores are a pale brown rather than yellow but otherwise it has typical ornamentation. The purple scale appendages at the tip of the thalli is also typical."

He went on further to explain that in 2010, A. gracilis was proven to be more closely related to Mannia than to other Asterella species and therefore could be called Mannia gracilis "if one wishes to ignore morphology in favor of DNA analysis," a statement which goes to show that I'm not the only one who has trouble accepting taxonomic shifts. Still, I couldn't be happier if Santa Claus had showed up on my roof with all the Christmas presents on my list.