Tumid notchwort (Lophozia ventricosa) is a common leafy liverwort that is common and grows on rock, humus and decayed wood. I usually find it most often on decayed wood in relatively moist and cool forest environments. It is one of about 60 species of  Lophozia and many of them are difficult to identify. Like most species of  Lophozia and many other leafy liverworts, the leaves are arranged in two rows along the stem and each leaf is bilobed.When you look at the leaves under the microscope, you can see each cell has several green chloroplasts that function in photosynthesis. The cells also contain a few glistening oil-bodies. These oil-bodies occur in a number of leafy liverworts and are often used to help distinguish between different genera or species.

The most distinctive feature of  tumid notchwort are the gemmae, tiny clusters of powdery-looking cells, that are produced at the tips of the leaf lobes. If you look closely with a hand lens you will see tiny light green clumps on the lobe tips similar to those shown in the above photo.

Under a compound scope, these gemmae are two-celled structures with angular cell walls. These gemmae are a form of asexual reproduction. The gemmae can disperse into the surrounding environment and, if they land on a suitable substrate, they will grow into a new plant. Quite a few species of Lophozia produce gemmae but tumid notchwort is one of only a few species that produce green gemmae. Other species will produce red, yellow, purple or gold gemmae.